The last 3 wheels I have had punctures / tyres fitted have all been damaged!!
1 was on the inside where obviously the jaws of their machine gripped the wheel without protection so took big chunks out. They also took the weights off with what looked liked screwdrivers so there were big scores around about the old weights. I took my wheels back to the place and the owner agreed that yes they had damaged them and would get them repaired but given they were diamond cut I changed my mind and never went back. Tried to sort it myself.
Another was a main dealer, while my car was in for a service I asked them to repair a puncture. Alloy was scuffed to hell. Its as if they put the face of the alloy down on gravel and then slid it about. They denied it of course even although every other wheel was in mint condition. I managed to machine polish this out.
Lastly took my wifes alloy in for a puncture repair and it came back with 3 big scores over the face of the alloy. I thought he was acting suspicious when he couldn't wait to get the wheel into the boot ASAP. I never even went back as I was just so p!ssed off. I just won't ever use those 3 places again.
I've had far too much damage happen to my cars / alloys when in the hands of garages for it just to be a bit of bad luck. I think they don't give a fcuk while your car is with them. I've decided any future tyre / puncture repair, I will take the wheel off the car myself, present it to the fitter and show him the condition of it. Ask him if he can do the work without damaging it and if he says he can I'll give them the job. That way they will be aware of how serious you are.
Also, any work on the actual car, I'll be doing the same by asking them to come and inspect it with you before it is booked in. If they say no I'll go elsewhere.
I'd happily pay more to know that they actually take care than just batter on in. Things like covering the wings with protection sheets if working in the engine bay rather than leaning over scratching the wing with the zip from their overall. I had that in the 80's on an XR2 that was in for some work. What a mess they wings were.
I think the more paranoid / anal you are about your car, the worse it is. The fact I don't park in car parks any more and am extremely cautious about everything about it, obviously makes me heightened to any wee mark the garage puts on it.
When I took my recently acquired Audi into the garage for some warranty work, I was met in the car park by a valet service. I was really dubious about letting him park it as I don't do side by side parking. Nose to toe is fine, anyway I gave him the keys and watched him, he had an SLR camera around his neck, parked my car then proceeded to take some pictures. Obviously to check for any damage the customer claims happens at the dealer. Now that is my kind of service