It`s more likely to be the regulator clip thats broken, there approx £10 on ebay, if your any sort of a DIY person you can do it yourself, look in your manual or get one and remove the door card, i would suggest you take the complete regulator mechanism off to do this, there`s usually three nuts to undo then you can remove the wires to the motor or remove this as well it all sounds a bit daunting but it`s pretty easy, have a look how the clip is fixed, you can pull it of the track one side and remove it, when you fit the new clip it`s hard to explain but you fit the cables then twist the clip round which tentions them then push it back on to the track it takes a bit of doing but if i can do it so can you, try it for the sake of a tenner.
Wakey George.
April 2012