Air Conditioner problems of the 2004 Buick Rendezvous

I purchased this car on June 23 and the next day it wouldn't start took it back to the dealership and they replaced the battery and the alternator said it was fixed but several hours later the car wouldnt start again took it back the next day and they said it was the air conditioner running while the car was off draining the battery so they took the fuse out and said they would fix it the next day but when I called to take my car to them I got no answer from them. Three days later the car overheated and I got it completely checked by a different mechanic to see why my car is running hot and he gave me a list of problems every head gasket is blown out and the motor is gone. He said that there was a recall a few years back on these types of Buick cars for the coolant and the wrong coolant was placed in the car and it messed up all head gaskets I immediately called the dealership but again no response I called the bank because I still have a 30 day tag and only had the car for two weeks but again no response I called Buick and spoke with someone to ask about the coolant recall and he said he would call me back in a hour and again no response. I asked for a carfax report and the dealership said they didn't have one but gave the couple behind me a carfax for their car the brakes and rotors are completely gone I cannot stop with my brakes I just have to coast so I want hit anyone this car will stall out on me without any warning. There has been no action taken from the bank or the dealership on how we can fix this problem they have all been ignoring and not responding to my calls texts or anything.