Send an e-mail to VX (GM) customer services, telling them what happened, and how you were treated.
Vauxhall Customer Assistance [vauxhall.customerassistance@uk.gm.com]
The reason I say this is simple:
I had a service for my VVT engine which needs 5w-30 fully synth, and they didnt use it. I sent an e-mail querying what oil my engine should use, didnt even mention the stealers name, and the next thing I know the stealers called me to say that could I bring the car in so they could avoid any uncertantity as to what oil they used with a free oil & filter change.
Coincidence?
I took the car back, was treated like a lepper, so sent an e-mail to VX thanking them for their customer service, and telling them how I was treated.
Next thing I get an e-mail from the garage with an apology.
Coincidence?
Seems that there is more than one way to crack an egg..........