clutch is classed as a wear and tear item i think, as you can abuse it with the way u drive.
if they took it off, sent it for analysis, and find that its been exposed to an increase level of torque without a shadow of a doubt, then you will have to pay for the new one and all labour costs (VW rates)
so i would just go to a reputable tuner who does a Sachs clutch kit and get it changed.
Kit is about £500, and fitting needs about 4-5 hours.
Also, if you leave it longer, you could damage the flywheel which then will be another cost to add on top!
Good luck.