Transmission Stuck In Gear problems of the 2016 Chevrolet Impala

When I was driving driving on the 91 freeway going to work at the speed, approximately 65 mph the transmission started shifting erratically like it was going to stop or it was stuck in the wrong gear. My husband was told to make an appointment to bring the car into GMC weeks later they finally decided that we could bring the car in only to be told that there was no lights on the dash board and they test drove it around the block and did not feel any issues. Than around October I was driving and the air bag light kept popping up on the dashboard and making a beeping noise around every 2-3 minutes of driving. My husband took the car back in to the dealership(penske Chevrolet in cerritos auto square) the technician unhooked the wires for the air bag and said that they would order the part. I was infuriated!! not only was I driving a car that I do not feel safe in but. I have to put my 12 year old daughter who has been having seizures life in danger as well. The technician also stated that there is a safety recall on the defective seat belts as well. One month later the dealership calls my husband and says that the part is in for the seat belt and airbags he installs it and calls my husband and says that the parts are defective. 2 months later today and still have no parts, no solution and the constant run around!.