Chloe Sparks ordered the five-bean chili dish at The Regal in Cambridge.
But when she started eating the meal, she realized it had meat in it, leaving her in tears.
Speaking to local media, she said: "When it arrived I naturally assumed it was what I had ordered but after one mouthful I knew it contained meat.
"I asked to speak to the manager but he didn't believe what I was saying, he kept telling me it was the five-bean chili. Eventually, he took it into the kitchen and I was offered a refund for the meal.
"I felt like it was handled really poorly, the manager's response was really rude and I was upset."
Never coming back
According to Sparks, despite being offered a £20 gift card as an apology by a different manager, she won't be returning to the pub.
The vegan - who ditched all animal products as a New Year's resolution - said: "My friends and I come in here about once every two months because it's cheap and a good night spot but I thought this was handled badly and it's put me off."
But it hasn't put her off veganism. "I stand by my decision to go vegan, it's good for me, it's better for animals and it's great for the environment," she said.
A statement from Wetherspoons said: "While we make every effort to deliver all orders correctly, on occasion mistakes can occur and when they do we apologize and do our utmost to put them right.
"We are sorry that this happened as we specifically cater for vegans and vegetarians with highlighted menu options.
"The customer has accepted a gift card after she brought this incident to our attention."