I have a question about the security system on my car?

Ok so maybe this is a long shot asking people on here and I will probably be told to go to a repair shop but I all ready did and still experiencing the same problem. I have a 2008 Chevy Aveo with a factory installed security system. Just recently something happened to it where when you hit the lock button on the remote instead of the doors unlocking or locking the three passenger door locks jump up and down and then when you open the drivers door the alarm goes off and the only way to stop it is by putting the key into the lock outside and turning it to shut the alarm off. Took it to be looked at was told it is what you call the Actuator in the drivers door that went out. Had it replaced and did not solve the problem, then was told it is the receiver module, but when I went to order the part was told my car does not have one. I was told to pay out a bunch more money to see what is wrong, but don't feel like doing this since it has cost too much all ready when the problem still exists. Has anyone ever had this problem and if so what was wrong or does anyone know what the problem is like maybe someone who works on cars and has seen this before? Thanks