This hapened on my ibiza about a 2 years ago. I had to take the door card off and window out to get at the motor, but once i got there it was a straight replacement for a new motor and locking mechanism from a scrap yard (cost me a tenner). I think you can get one from any similar VW group car as mine was from a polo. Seemed to sort the c/l out right away, and i had no probs after that.
Morv, April 2007