I presume that you have contacted the customer services on 01246 223000, Speak to them again and they will start a procedure for you to get the vehicle checked out and investigate your concerns,
As all companies that do work on customers vehicles things do go wrong and if there is just complaint it will be put right , if the damage caused was not on the pre inspection and there when completed then it will be put right .
As for scratched glass, one possible cause that happens at this time of the year is many people de ice there car with an unsuitable implement , be it a credit card or cd case, this can and will cause scratches to the windscreen,
It is in no ones interest to have customer complaints which we all have from time to time, its how these complaints are handled which makes all the difference , like I said earlier , speak to customer services who will log it and let them get it checked out for you and they will pursue it to an amicable conclusion ..........
let us know how you go on .......