Insufficient service

Our air conditioner was not working. They sent out representatives 3 different times in August. The last guy told us it was an A Coil that had to be replaced but DTE did not cover the cost. We had an outside contracter come out and replace the A Coil. He said I replaced your A Coil but that wasnt the reason it wasnt working. It is a leak in your condenser unit. We had to pay $600 for an A Coil which we did not need because DTE told us that was our problem. We then had to pay $75 for the repair in the condenser unit. I contacted DTE to see if they would reimburse the $600 because they are the ones that told us we needed an A Coil. I talked to a Mr. Michael Romeo who said he would look into it. I have tried to call him 3 times and he will not return my call. We would never have gotten an A Coil put in but DTE's representatives told us that was why our air conditioner wasnt working. We have been a faithful customer of their Home Protection Plus for many years and have not had any complaints but this just doesnt seem fair.