I learned to not really deal with shops unless they specialize in the type of car you have, at least when it comes to custom stuff. You would think a shop with classics in it, or higher end cars, or lots of fancy lifted trucks with extensive exhaust work would cut it, but they just see you as another kid with a rice [kraut] burner that wants a fart pipe, and they assume you probably just don't care as long as you get results.

Not all shops are like that though - and you do get what you pay for - but you can't expect much when they probably work on everything under the sun, and most of these non "trick out your car" shops that just do general exhaust work probably spend 90% of their exhaust fabbing time fixing busted up berettas and old cars with rusted out shit so they're not usually looking to make the best quality stuff.

Sucks to hear, but fix it so it doesn't happen again, and move on. Chances are taking it to the shop won't get you anything but doubletalk from some fat surly greaseball.