CHOCOLATE LOG: The cake sent to a client by Oh Cakes owner Emma McDonald. The wording on the sign has been partially blurred by Fairfax Media.

A Southland cake maker has come under fire on Facebook after she set out to teach a client a lesson by sending her a cake in the shape of a giant poo with a sign saying "eat s..t".

Oh Cakes owner Emma McDonald, of Riverton, sent the cake to the client on December 20 after she said on Facebook the client had got angry at her about rescheduling a meeting.

She refused to speak about the incident with The Southland Times.

McDonald said on her Facebook page that the client had won a $50 voucher for a cake, which was then reduced to $30 by McDonald because the client owed her $20 for a separate business arrangement

When McDonald asked her, via text, what sort of cake she wanted, the client said her girls "like choc cake".

After the cake was picked up by a client who was attending an engagement party, McDonald said on her Facebook page:

"Your [sic] left with a $30 voucher and you want a cake still?? ok cool- give me some ideas?? oh wait you have none apart from wanting chocolate, I have a brilliant idea for your cake!!!- so here it is, your turd cake! Hope you learn your lesson."

People expressed their disappointment on her business Facebook page after the incident, but McDonald has hidden the comments since being contacted by The Southland Times.

When an argument among several Facebook users broke out on a post about the "turd cake", McDonald posted her private correspondence with her client on her Oh Cakes Facebook page, making it possible for all Facebook users to read.

McDonald said on her personal page just hours after being contacted by The Southland Times that "basically she [client] deserved what she got".

In the same post she went on to say that she has given food and cakes away to people in need and donated clothing to charities.

"I give one lady a piece of my mind and everyone thinks we are bad people. Well I don't think we are."

The client was unable to be reached for comment.

But in a text from the cake client to McDonald posted on Facebook, she said: "We r [sic] just at my sister's engagement and got your cake, we and every1 [sic] else is absolutely disgusted."

The Chamber of Commerce president Sean Woodward said the situation was not a responsible way for a Southland business to act. "Southland is a relationship-based place. I don't condone it at all."

Woodward said there were plenty of avenues for Southland businesses to take if they encountered problems with customers, including contacting the chamber for advice.

"This time of year, people get a bit stressed."