Customer came in and her air suspension was not working. We hooked up to the computer and got 2 codes. One was a C2302 , Level sensor error plausibility. C2303 Reservior error plausibility. After running multiple diagnostic tests we informed customer that we needed to replace the rear leveling sensors and it still could need the reservoir. Quoted for both. Talked to customers father and informed him of the information. He said ok to order the level sensors and go from there. Level sensors came in from Jaguar and we replaced. Retested air suspension system and test drove. Air suspension was working exactly how it should work. Customer came to pick up her vehicle. We called her father and informed him that we replaced the sensors and retested the suspension and everything was working just as it should.Father then paid the bill. Showed the customer the parts we had replaced and went over the bill with her. Informed her that we had also discovered her oil leak and that it was coming from the sealing ring off of her oil filter. Informed her we replaced her filter and topped her oil back off free of charge except of the cost of the oil filter. Customer informed me that her boyfriend had changed her oil and that he must have damaged the sealing ring when he put on the oil filter. Informed customer that there is a 12 month 12,000 mile warranty on all of our repairs and that if she had any issues to call us and we would take care of it. Weeks later we receive this sure critic low score. The owner and I have made many phone calls. We have sent out texts and e-mails and to this day we still have received no response back from her.We stand behind our work but we can not make it right if the customer will not answer our phone calls.