I can't believe people like this exist. Is Brenda some sort of sociopath, I guess? That's low-down, immoral behavior. If I were you I'd slip some rat bait in her walk-in and then call the health inspector! I guess that would be sinking to her level, though.
Well, good luck... I guess I don't have to tell you that I was on Jill's side before I even heard the end of the story!
PS- Really didn't know how to fillet a fish in a fish shop, eh? Got your work cut out for you there!