During my MOT, the 'shaker' upset my electric windows which now do not work at all, dead at the switches all round. The garage have tried to fix it but were not able to resurrect them, describing the wiring as 'a bit of a bird's nest' and recommending an auto-electrician.

It's a well-known chain, and I'm on otherwise good terms with them and happy enough with work done over a couple of years. One of the windows was unreliable but power always got to the switch, which is not now the case so the damage is definitely more significant. Do I have any specific rights in such a case, should I wish to push harder for some culpability or redress?