Repair exhaust

My wife took my truck in (I had out of state tags at the time) to repair the exhaust system. I had no other problems. The mechanic went on about how much my truck was "a piece of junk. Offer to sell us a car he had fixed up. When I got my truck back, I no have difficulty starting it, there is exhuast coming out from under the cab of the truck and I now have a leak in my transmission. None of this was happening BEFORE I took it in. This guy is either crooked or incompetent. I wont give him a second chance to prove to me which one it is.