yes this garage does exist ph 045899196, but surely your arguement is with the dealer not the people he farmed the work out to .this is a very common practice with dealers who dont have their own workshop.i wouldnt imagine they will entertain you as they didnt do work for you.
did you have the car checked before you bought it,?
alot of people these days are all shouting clocking as soon as a problem happens with a car ,shouting clocker to a dealer without you having your facts could drop you in a right pile of crap,