Body Shop Thought I Wouldn't Notice

[BMWX5CHI]

So as some of you already know I was rear ended a couple of weeks ago. I decided to go with State Farm's Select Choice Repair Shop. I went with Guy and Sons Auto Repair. Turns out they ''Repaired" my back bumper and repainted it which is fine, but they didn't repair my muffler(s) properly.

So now I'm a little upset with the repair. I don't know which muffler is making the noise but it sounds like it's leaking as if it was cracked or has a hole or was incorrectly installed. Here is the picture of the ''Repair'' they did on the muffler(s). I called up State Farm and explained to them what I found. So before I go tomorrow and confront them guns blazing, what do you guy suggest? and does anybody know what is that grey crap they put on my muffler ? Look how crooked one of the bolts are.