She wrote: "Clearly not dog people... I won't be trying your place at all and consider yourself unfollowed."
She then reviewed the restaurant giving it a terrible one star and writing: "Terrible service and terrible food."
But the restaurant noticed and called Ms Farran out on the 'fake review".
Pastels wrote: "Because you didn't get picked is it appropriate to leave a one-star which is clearly a lie you have not tested our food.
You've heard of fake news, now check out fake reviews 😂
Posted by Pastels - Burgers and Shakes on Wednesday, 28 March 2018
"We also have dogs ourselves... free piece of lettuce for leaving a FAKE review."
Gage Dunstan, 29, who runs the restaurant, told The Star they would honour the offer of free lettuce if she came down to try their food.
"Anytime we get a bad review we message the person and try to solve the problem, but with this review, we had proof that she had not been and was slandering our business," he said.
"We would never call out a genuine review.
"She said we must not be dog people, but we donate dog food to a lady who feeds homeless people's dogs."
But Pastels owner Gage Dunstan was left understandably frustrated, telling Sun Online: "It's just not needed.
"Business is hard enough with people trying to sabotage what we're doing. We always welcome genuine reviews, however it's just not fair when they've never even been."
Many people left comments siding with the restaurant owner, with one calling the Ms Farran "dangerous".
"Just need to smash my phone and maybe I'll get free food," joked Stacey Crombie.
The woman won a free side in the contest, called her a "stupid girl" and praised Pastels for its food and service.