Horrible Experience at Audi Centre Northcliff, Need assistance

Took my car in due to a bit of shaking when idling, and unusual oil consumption. The dealership quoted me R10600, which I declined. I was told they would perform an oil consumption test, which was apparently not successful for some reason.

I fetched my car later on and it had no power, it was shaking all the time, smelled of oil.

They obviously broke something which they do not want to admit they did. They told me there's an injector fault which they only picked up after some tests they ran.

I need assistance, Please.

Note the car has been there since Monday the 10th June :)