Other major phone manufacturers including Apple and Sony say the problem does not affect their handsets

This means many users are racking up huge bills without even realising

A mother was hit with a staggering £1,200 in phone bills after texting hundreds of smiley face emoticon symbols that weren't included in her 'unlimited' £31-a-month contract.

Paula Cochrane, 48, had no idea she was being charged 40p per emoticon by her contact provider EE and said she was 'raging' after the company only offered to cut her bill by £100.

She is one thousands of people with certain Samsung handsets who have been stung by the charges - which are a result of text messages being converted into pricier picture messages when the popular face symbols are included.

Not happy: Paula Cochrane has been hit with a staggering £1,200 phone bill after texting hundreds of smiley face emoticon symbols that weren't included in her 'unlimited' £31-a-month contract

Speaking to the Daily Record, she said: 'I am raging. I have never heard of this before and I've had a mobile phone for years.

'Even the staff at my local EE shop were shocked when I told them. They knew nothing about it. Do EE really think I'd run up these bills if I knew the cost? It's daylight robbery'

'I feel violated that EE have withdrawn more than £1,000 from my account for a £30.99-a-month contract. It's totally unacceptable.'

The hairdresser, of Airdrie, North Lanarkshire, said that when her bill for November arrived and was more than £100, she assumed she had used the phone for longer than the allocated minutes in her contract.

Huge charges: Smiley dace icons are converting text messages into pricier picture messages costing many smartphone users a fortune as they are unaware of the charges

She later called EE to get to the bottom of the charge and was horrified to discover that her combined bills for December and January were almost £900 - and her pending charge for February has already exceeded £150.

She was told by an adviser that the Japanese smiley face symbols were being sent as picture messages.

An EE spokesman told MailOnline: 'There are a number of factors which can affect whether customers are charged for sending an emoji usually by the settings on the handset and so is a manufacturer – rather than a network issue.

‘EE has a help section on the website which details instances where an SMS may convert into MMS.'

HOW YOU COULD BE HIT WITH HUGE A BILL FOR USING EMOTICONS If you are using a pre-2014 Samsung handset, including the Galaxy S1, S2, S3 and S4, as well as the Galaxy Note 1, 2, 3 and Galaxy Ace, you could be hit with huge charges for sending emoticons in messages, no matter what network you are using. This is because a number of their older handsets convert texts into picture messages when you include the smiley face icons. Picture messages, or MMS (multi-media service) messages cost far more than standard texts - meaning users can be hit by huge bills if they send dozens of the symbols every day. Apple, HTC, Nokia and Sony have all said that including an emoji or emoticon symbol in a text with their models will not convert it into an MMS. If you own one of the Samsung handsets affected, you can stop this from happening by taking the following steps (instructions may vary depending on what handset you use): 1. Open SMS 2. Select settings 3. Scroll to Input mode 4. Select UniCode instead of automatic OR Select GSM alphabet (depending on handset) You could also use an app rather than your network to send messages. If you're out and about you'll be using your data but if you're using wi-fi, there's nothing extra to pay. Step 1 and 2: Enter your message setting on your Samsung phone. Depending on what handset you have, the presentation of these options may vary Step 1: Enter your message icon Step 2: Select message settings Step 3: Scroll to Input mode Step 4: Select GSM alphabet Advertisement

They added: 'Mrs Cochrane did not query her bills with us until the end of January.’

Ms Cochrane had used smiley faces that were on her phone's toolbar and not from a downloaded app.

She is not alone - as Consumer website MoneySavingExpert has received a huge number of complaints about the issue.

In some cases, especially on older handsets, the emoticons are converted into MMS (multi-media service) messages, which can cost up to 40p each depending on what network you're on.

And other smartphone users who create their own icons from full-stops, colons and brackets have found they are being converted into emoticons - running up the same charges.

Older handsets known to be affected include the Samsung Galaxy S1, S2, S3 and S4, as well as the Galaxy Note 1, 2, 3 and Galaxy Ace.

A Samsung spokesman told MailOnline: 'We can confirm that as of April 2014, every Samsung mobile device has a default setting that classifies emoticon images as an SMS and not an MMS.

Popular craze: Emoticons, also known as emojis, are used to portray a texter's mood of feelings and are commonly used by people with smartphones

'For older devices, if a message is going to be converted from an SMS into an MMS, a warning message is displayed to inform the user of this.

'We advise our customers to check their mobile phone tariffs if they are unsure of any charges related to SMS and MMS as well as the advisory notices displayed on their handset.'

Apple, HTC, Nokia and Sony have all said that including an emoji in a text will not convert it into an MMS.

... SO WHAT ARE EMOTICONS? The word emoticon comes from emotion and icon Also known as emojis, they are used to portray a texter's mood of feelings - and in the earliest form were produced by sending combinations of colons and brackets to create facial expressions. Many smartphones now come with a vast collection of emoticon symbols, while apps containing thousands more can also be downloaded. The current form of emoticons first rose to popularity in Japan. Advertisement

In the autumn, Ofcom conducted a survey looking at all the reasons why people received higher-than-expected bills.

Emoticons being billed as picture messages had affected four per cent of those who responded to the survey.

One woman, who was hit with a £209 charge, told MoneySaverExpert: 'I phoned up EE to be informed that as my son has been including emojis in his messages, they are charged as picture messages, and not included in his contract.

One O2 customer said she had also been hit with a large bill and was told emoticons were classed as picture messages on Samsung phones.

She said: 'EE has now agreed to halve the bill, which I suppose I will have to accept, but I would just like to warn any other computer/smartphone illiterate parents of the pitfalls!'

Speaking on the issue an Ofcom spokesperson told the Daily Express: 'We are aware that in some circumstances SMS may be transferred into MMS (for example, where one text is sent to multiple recipients or where an emoticon or emoji is used).

Affected: People have reported the problem while using a number of Samsung's handsets

'Based on our previous engagement with mobile providers about long texts/texts sent to multiple recipients and the subsequent conversion to MMS, our understanding is that the conversion is a handset issue. How that message is subsequently charged would be a mobile provider issue.

'However there are rules on transparency – we would expect mobile providers to make clear to consumers how much MMS cost and when such charges would apply.'

HOW MUCH DO PICTURE MESSAGES COST FOR EACH NETWORK? If you are on a monthly contract, the amount you pay for MMS messages will vary depending on what network you use. Here's what each major company charges: EE: 40P O2: 40P Orange: 40p Three: 19.8p T-Mobile: 20P Virgin Mobile: 40p Vodafone: 40p Advertisement

An O2 spokesman said: 'If a customer is using a smartphone to send text messages to more than one person at the same time, they could be charged the cost of sending an MMS.

'It can also happen when the message contains icons, emoticons and symbols or an email address. And some apps (such as Facebook) that integrate with a customer’s contact list in their smartphone may result in an MMS charge too.

'To stop this happening, customers should make sure they don’t include symbols, icons or emoticons and also disable the integration between their contact list and apps like Facebook.