Thrifty Car Sales

I purchased a 03 Lincoln LX from Thrifty Car Sales Approx Mar 1, 2009, I made all payments timely without missing a payment. I even paid off the car 8 months early. Thrifty reported my credit information up to the time I paid off the car. Then they not only stopped reporting they deleted all payments from the 3 credit reporting agencies, I spoke with the gm(mike) on several occasions and told this would be corrected it has not been corrected, more so, my credit score would be much higher than it is now if they would report it as they stated they would do, and continue to report for ten years because it is good credit. Please Help! Herbert Jerrido