Adaptive air suspension

V8 all wheel drive automatic 63,000 miles.

Recently, my vehicle air suspension system failed. For about three days, I experienced not being able to adjust the ride height. After having the front brake pads replaced, it seemed to have totally deflated in the front and was too low to back out of the repair shop without using some boards under tires to get the car over the doorway hump. I had the car transported to the Audi dealer for repair. They advised me that a relay had failed and caused the pump to overheat and fail. What should this repair cost? And, as the pump was quite noticeably noisy when in operation, would its continuous operation be obvious? How long would it take a pump to fail? Note, the car was much lower in the front after this failure and scraped when going over a small rise in the road, whereas the rear seemed at its normal location for lowered height. The front tires were noticeably below the wheel well opening. Thank you in advance for your input.