Chrysler Repair: DOOR LOCKS, door latch, chrysler dealer

Question
I have a 2005 Town & Country van.  The locks are to automatically locks once you reach a speed of 18 mph but they don't...they don't lock with the key pad...they don't lock manually either.  I have taken my van to our local Chrysler dealer 6 times for the same problem which they temporary fix.  The "door latch" has been replaced and the "door switch"  Can you help?!!!!

Answer
the auto door lock can be changed with a setting change in the BCM at the dealer.
Will all door locks not work, will all of them stay locked and cant use manual? Tell me what was replaced  and done each time.
I live in the Atlanta area I would be glad to look at it for u.