Audi-recommended body shop breaks safety features, both deny responsibility

A few weeks ago I took my A8 to have the front and rear bumpers sprayed and took it to a body shop that was recommended by Audi Claremont.

When I fetched my car I was satisfied with the spray job, bar the overspray, however after leaving a warning appeared saying that the adaptive cruise control and Audi Braking Guard were unavailable because of no sensor vision, something which had never happened before.

So a few days later I take the car back to CC's MobiFix in Ottery and speak to the owner Christopher. They take the bumper off and put it back on and lo and behold the warning still pops up and these 2 important safety features are still not working. The plastic insert under the bumper is also still hanging out because that also ended up being broken somehow.

Christopher, who does body work for Audi Claremont - claims this is out if his hands and that he's not liable for having the sensors recalibrated because "he didn't know" this would happen, even though Audi Claremont sends cars to him every week. He is claiming ignorance as an excuse for shirking his responsibility, which is to have the sensors recalibrated. He says that I should have told HIM that the sensors would need recalibration if the front bumper comes off and that it's MY responsibility to know my car..... seriously? I've had the car for 2 months while he's been spraying Audi's and BMW's for years and should know what he's working on. Why should I pay for the safety features he broke? What normal person would expect the client to pay for something they broke? Why are neither of them taking responsibility?

Does the person at Audi who recommended CC's MobiFix get a kickback? Why else would they use a non-Audi approved body shop? Do they add massive margins while the client thinks their vehicle is going to a reputable shop because, well, Audi recommended them, so they have to be good, right?

Wrong!

They both throw their hands into the air and say it's neither their fault nor responsibility - which is as disingenuous as it is immoral and idiotic. I've given Christopher and Audi multiple opportunities and asked multiple times to sort this problem out but both just say it's out of their hands..... even though if it weren't for them this wouldn't have happened!

Long story short: Audi recommended a body shop that broke 2 important safety features and neither Audi nor the body shop are taking responsibility and expect me to pay.

Beware any recommendations from Audi Claremont and beware CC's MobiFix.