Autosure Warranty Corp

I had a 3 yr powertrain warranty from this company for a used car. The conditions required stamped proof of regular oil changes to be mailed in and received by AutoSure within a short time (1 or 2 weeks) after each oil change is done. I always had the oil changed within the required intervals but misplaced one of the stamped papers and sent it in late. I was concerned so I called the company and was told that there was nothing they would do. I was told that I didn't send it in in time, those were the rules, and so they were cancelling the warranty. They would not be persuaded otherwise, and treated me quite rudely. I consider this to be unacceptable, and I would not recommend this company.