1999 Audi A4 CAM Seal Replacement

My son bought a 1999 Audi and took it to a repair shop to have the oil and transmission fluid replaced. They took him it need a new sirpentine belt and cam seals replaced, At the end of the day, they called and said "they replaced the seal and when to start it up. It would not start. They checked the cylinders and there was no pressure. They investgated more and said the timing has jumped about 5 teeth foward, because a belt tensioner had failed. Now they replaced these parts and still no pressure in the cylinders. Expection is that the valves are bend now. They are say 1500.00. My thinking is that they screwed this up when replacing the seals.

The car ran perfect before they started working on it.