Tyre Garage Damaged My Alloy Wheels - Are They Liable To Pay?

I had my two front car tyres changed last week & despite them being immaculate and damage/kerb free, they came back scratched to bits.
I went straight back to the manager to complain (I had taken photos of my alloys before I left in in their care like I always do when the car goes for services etc.) so that is my comeback.

He admitted it straight away and has offered to get them refurbed and will be picking up the tab.

It transpires that this place he is talking about is his fathers place (combined with a valeting side to the business) so I took a run down this morning to see if it looked decent but it looks like a back street garage and doesn't even have a sign whatsoever above the premises and looks like it's run out of a single garage.

I saw one guy pottering about doing nothing and my first impressions were that I would not be happy with my car being left there. He even said that if I dropped it tomorrow then it could be done in half a day the refurbishment? Does that sound right?

What I want to know is, am I within my rights to select a few places I feel would be suitable to do the work and present him (garage guy) with the quotes/bill or am I 'obliged' to have it done where he suggests?