Harvey Norman customers are angry after being told furniture they bought in an online sale was wrongly priced.

Hundreds of Harvey Norman customers are irate after being told furniture they bought online in its "biggest ever retail sale" on Thursday morning had been priced incorrectly.

After realising the botch up, the retailer sent a generic 'error' email to all of the 327 customers who purchased items in the sale, leaving some "fuming" their personal details had been shared.

The furniture in the sale included three piece lounge suites for $103, two piece suites for $95 and a wooden tables and chairs for $159.

READ MORE: Paying for someone else's mistake

The email said: "Unfortunately this morning between 0.01am and 8.00am there was an error with the Furniture department pricing. We apologise for this genuine error and wish to advise that a customer service person will be in contact with you shortly to discuss your purchase".

Kirstin Belton from Manawatu said she did not think there was an error because the retailer was having its biggest ever retail sale that was clearly stated on the website.

She had called Citizens Advice Bureau to find out what her rights were after she saw money had been taken out of her account.

Belton believed she should be able to keep the product for the price she paid.

"I bought the furniture for $95 in good faith and there was no 'then' and 'now' price on the website."

Chanelle Fraser-Wood from Oamaru was up at 3am with her child that could not sleep and saw a friend had posted about the sale on a Facebook page.

"I saw the suite for $159 and woke my husband up. When you see multiple products at low prices, you don't think there is a price error. I thought it was one of those diamond in the rough sales. They are not unusual these days."

She was hoping she would get to keep the furniture because she bought it in 'good faith'.

"I work in retail and if we price something wrong, we have to sell it at that price," she said.

Charlotte Butcher from Pukekohe said she was under the impression she was paying $159 for a couch but her credit card had a pending transaction of $1359.

Monique Aroha from Rotorua, who bought a couch for $93, said she was upset after Harvey Norman told her because it was a genuine error and not bait advertising, they could not sell it at that price.

They offered her a refund and a $100 Harvey Norman Gift Voucher.

"I went online to not only see something amazing but something that my family could do with. A beautiful lounge suite, knowing they had a great sale I just thought this was part of it.

"This is false advertising and from what I have learned, if you have a set price then that's what you pay. It's not my fault they stuffed up."

PRIVACY BREACH

The mass generic "error" email has angered customers, who feel their privacy has been breached.

Belton had been receiving hundreds of irate replies from other customers

"Everyone is angry that we have all been cc'd. I called Harvey Norman about that and they said it was human error and would try to rectify it by recalling the email but the damage is done," she said.

One customer who did not want to be named said everyone was fuming:

"The cherry on top is when they sent this email, they breached every customer's privacy by copying everyone into the email . Now hundreds of fuming customers are not only furious that Harvey Norman aren't willing to honour their advertised prices at which they sold their goods, but they are now receiving emails from all of the disgruntled customers on that receiving email list who are hitting 'reply all'".

Butcher said she was getting rude comments from some of the customers about her business "unique" logo on her email address.

Harvey Norman, who could be hundreds of thousands of dollars out of pocket, have not replied to a request for comment.

Consumer NZ advisor Maggie Edwards said eight hours was too long to realise a mistake had been made.

"Even if they thought it was too good to be true and went back a few hours later, the prices would still have been the same," she said.

There had also been blatant "in your face" advertising on TV, so people knew there was a sale on and would not think there was an error.

She advised the customers to pursue with their fight because they had "nothing to lose".

"If Harvey Norman has any sense, it will honour the sales, especially with the privacy breach."

Even if Harvey Norman refer to terms and conditions, they would have to abide by the Consumer Guarantees Act, she said.

LEGAL OPINION

Lawyers said the customers would have to try to prove they believed the price they bought the good for were genuine.

Michael Wigley, principal of Wigley Law, said where there was a genuine mistake by Harvey Norman and the buyer figured the price was too good to be true, it was unlikely they can legally force sale at the low price.

"If a customer genuinely thought there was no mistake, then in theory they can enforce the contract for the low price," Wigley said.

"However, say the lounge suite full price was $2000 and the sale price was $100, a customer is likely find it difficult in practice to persuade a court or disputes tribunal that they thought the price was genuine."

Alan Knowsley, a managing partner with Rainey Collins Lawyers in Wellington, said it appeared a contract had been formed and the onus is on the shop to seek relief from the contract.

The shop could seek relief under the Contractual Mistakes Act if the price was a mistake and it can show the buyer knew of the mistake.

"This does not mean that the buyer has to actually think the price is an error. A substantial inequality in what is paid and what the goods would be worth could lead to a Court concluding that the buyer "knew" there was a mistake."

A buyer could seek to enforce the contract if the shop refuses to complete the transaction and the shop would then seek relief, he said.

"If it is a genuine error and the price is substantially out of line the Court might grant relief to the shop. A small difference in price will not be sufficient but each case depends on its facts."

The emails should have been sent individually and there was a clear breach of privacy that could see Harvey Norman face compensation claims, he said.

Office of the Privacy Commissioner spokesman Sam Grover said the depth of the breach sounded limited to email addresses and the cause sounded like human error.

"This sort of breach is relatively common and an easy mistake to make. We advise Harvey Norman to follow the breach guidelines on our website. We would take any complaints from customers seriously – the same way we do for all complaints."