2009 Aveo radiator hose broke got fixed now smoke is coming out of engine...

My radiator hose broke while we were driving home from work. Went to Auto Zone and got new hose (upper hub is what I was told) next day car ran fine and then when driving to work smoke started coming out from under the hood. Parked the car for 2 days trying to get a slot with my mechanic. Well, he kept the car for a day and calls me to tell my that it was my thermostat something about under the jug the holds the antifreeze. Cost me $300 to get it fixed. Not even 3 hrs after getting it from the shop it started all over again. But my mechanic says the fan works and the sensor is good. Mechanic said that Auto Zone also sold me the wrong hose because it bends at a spot and no matter what wont straighten out. So what else can it be?? What should I look for??