One thing that you should do right away it to write a letter to GM home office and the district manager and the dealer that sold it to you detailing the problems you are having.
Actually you should learn to do this after the second time you have a problem and I would have when they had my vehicle tied up for more than a week.
For what it is worth, this is the good advice that my attorney advised me to do anytime I start to have a problem with anyone. His thought is that it makes good evidence just in case you should have to go to court to try to settle something. It also causes them to have to deal with it and not put it off thinking you will go away or forget about it. If you write a letter then they have to reply and you just never know what might get done that might have been passed over with just a phone call.
As he is always telling me. "At least you have some proof to show a judge and jury that you have been damaged and you asked them nicely to help you get it fixed and they did nothing" (ALways ask nice the first time) He says it sure makes his arguments easy in court when he has a letter to backup your complaint.
BTY: I had him hand me my hat in a small claims case 15 years ago because I didn't have the proper cause in my contract. The next time I needed a lawyer I called him and we have never lost one since I started to listen to him.
Pantera