What could be wrong with my car?

My car has push start a 2015 Altima. Well for a month it said it needed a new battery it was low. Well I went to the dealer on last Friday to get a new battery installed to the key. Well a day later the car started to say the same thing. It needs a new battery. I called one lady said they key may need to be reset to the car. I m thinking he would have done that when I was there. But the next day I was in the drive thru talking on the Bluetooth connected to the car and the speaker made a loud noise as if it blew out. So I looked at my car radio and it was restarting. So then it reset the time on my car and I called nissan again. They told me to come in next Tuesday it doesn t sound like it has anything to do with the key. Ooo an I reprogram my favorite radio stations to the car and when I got off work today it wasn t programmed anymore.