A "traumatised" vegan mum claims KFC staff accidentally gave her a chicken burger at a drive-thru and then laughed at her for eating it.
Vanessa Franco ordered what she thought was the fast food chain's new vegan Quorn fillet burger.
She said she was horrified when she took three bites and suspected that it was chicken because the burger "tasted different".
The mum claims she complained to staff at the restaurant in Colliers Wood, south-west London, and they started laughing before replacing the chicken burger with a Quorn one.
KFC said it would speak to staff and offer Vanessa a free meal as a gesture of goodwill.
Vanessa, who recently turned vegan and has been a life-long vegetarian, said: "I realised the texture tasted different.
"I drove back to KFC and asked them to confirm it was a vegan burger. That’s when the girl who served me told me it was a chicken fillet burger.
"She then called her colleague, who told me to come inside.
"She also said if I took bites out of it then why didn’t I notice it was a chicken burger? I explained I have been a vegetarian my whole life."
With her baby son asleep in the back seat of the car, Vanessa, of Pollards Hill, south London, wanted to carry on the conversation in the drive-thru.
But she said staff insisted she come inside instead.
She added: "I then went in with him [her son] and had to wake him up, the manager then came out.
"That’s when he gave me a vegan burger, didn’t apologise and laughed and said 'you should have known it was chicken'.
"All of the staff stood there staring at me. I felt humiliated and have been left traumatised due to not only a life style choice but also religion being broken and made fun of.
"I was speechless and can't express how disgusting their customer service was."
KFC later apologised.
A spokesman said: "This isn’t great and we’re really sorry for what happened here.
"Our vegan burger launched last month and we took its arrival seriously – putting strict new processes in place to make sure it’s served properly, including the use of separate coloured tongs and storage units.
"We’re following up with the team to remind them of the importance of getting this right and will be offering the guest a free meal on us to put things right.”
Earlier this year, Nic Kent, 27, from Nottingham, said she was "heartbroken" after ordering KFC's vegan burger and biting into one with chicken and cheese instead.
Nic, a personal assistant and decorator, said she felt sick and had to brush her teeth afterwards.
She said the box was labelled "zero chicken" and she bit into the burger without checking to make sure it was the right one.
However, a chicken burger was put into the box by mistake, she said.
KFC later apologised.
The fast food chain launched its original recipe Quorn burger on January 2 this year.
it is billed as a meat-free alternative to its chicken fillet burger, containing a "bespoke" vegan Quorn fillet coated in KFC's blend of 11 herbs and spices, and served with vegan mayonnaise and iceberg lettuce in a soft-glazed bun.
