Can you use the button on the inside of the drivers door to unlock the doors and get out? Does this require a few attempts?
My central locking actuator went in the drivers door - it started temporamental needing 2 or 3 attempts to unlock and be able to open the door (from both the remote outside the car, and the button on the inside of the car), but it got worse. If it is this - the part is just over £200 fitted at an Indie, but it was covered under my aftermarket warranty so should be the same for others.