What would cause door to lock when unlock is pushed inside vehicle?

2000 Grand Prix GTP Coupe. Key Fob was working only intermittently with the trunk unlock feature only. The doors did not function at all, but using the switch inside of car, all work great. I had the car scanned for a check engine light and while I was there, checked my fob against a battery display to see if it was working. it showed ok for the trunk and lock function but not the unlock. I went to get in the car and noticed that the doors were locked. I thought maybe the tech locked them by mistake. I tried the fob but nothing worked. The window was down so I unlocked the door from the inside. When I opened the door, the alarm sounded. I silenced the alarm, put the key in the ignition, and when I started the car, the alarm sounded again. It did this every time I opened the door or started the car for a day then seemed to be ok. Now, when I push my switch inside to unlock, the actuator works in the opposite and locks the door. Please help! Thank You