National Tire & Battery [NTB]

A year ago, i had paid 600.00 or better to get 4 new Rotors on my car, and from the moment i left the shop, as i drove down a hill, i heard a terrible clanking sound. This only happens when i go down steep hills, or too many hills. I brought it back several times since this happened, and was told everything looked good, however, it is recently making a very loud clanking horrible noise as a i drive down the hill even worse. I am tired of going to NTB asking them to fix this. My son is my witness to what we heard when we left NTB after getting rotors put on. We have never heard this in the car before that. After spending many weekends at the NTB, and wasting my time only to be told that everything is fine when it clearly is not, i would like this to be fixed without charge because of their mistake to begin with. I have spent thousands of dollars at NTB in the last years, and i wont do business unless they correct this, and do it without charging me again. The men at this business know who i am, because i have come in there with this issue many times.