Small Claims Court is your friend, in this situation. You can represent yourself, just bring all of the evidence and either obtain a letter from the second mechanic, or have him show up as a witness. When the company receives a letter/supeona, they must send legal representation tothe court you filed your claim in. The company will not want to have to incur the cost of sending legal representation to your courthouse to represent the charges. Your trip to small claims court will cost their company more money to just show up than the amount of refund you're after. No company is going to spend thousands of dollars to fight a couple of hundred dollars.