Amy's Baking Company and the Rose+Moser+Allyn Public & Online Relations group lasted a whole five days.
The PR firm said it has ended its relationship, a day before the restaurant is expected to have its grand re-opening week.
"It's fair to say, that while we were in agreement on some approaches, there was disagreement on others," said Jason Rose of Rose+Moser+Allyn.
"The week has been an exciting one, a very exhilarating one and unquestionably a tremendous professional challenge."
Also, the scheduled press conference before the re-opening has been canceled because of lawsuit threats from Fox.
A spokesperson with Fox's Kitchens Nightmares declined to comment.
Sunday, Amy's Bakery held a job fair and hoped to hire at least 10 people.
There have been more than 1,000 reservation requests for the week.
Ten percent of this week's proceeds will go to benefit the Megan Meier Foundation, an organization dedicated to combat the effects of cyber-bullying.