Sears review: defective product replacement policies

Bought a starter for riding lawn tractor, 4 15 2015 but did not work. Went to get help at the place where I bought it (Sears Parts Center) and was given a phone number to contact a Sears mechanic [protected] & [protected]). I learned the numbers were for Sears Customer Care Department. The mechanic instructed to do some tests and waited on the phone ... I gave him the results and he concluded that the starter was defective and told me that he would send a replacement starter with a return label for the defective starter. After 2-3 months I did not get starter. In trying to return starter the clerk at the Sears Parts department told me that they were not allowed to take back parts over 30 days since purchase and follow up call to Customer Care Department was told that they are not allowed to replace parts not directly bought from them. Also they had no record of the mechanic agreement. Please help me get the defective part replaced.