AIM Used Auto Parts LLC This company sold me a defective engine and is refusing to warranty it. Tampa FL

Was sold a defective engine and told it will not be warrantied. Purchased an engine from AIM on 1/23/13. The engine arrived with several problems (I purchased it on the assurance it was a tested, working engine) including a missing compressor and a cracked throttle body. I contact AIM promptly and it took them until 6/27/13 to rectify these two issues. (Other issues I noticed and reported were never rectified.) I got the engine started on 8/17/13 and immediately noticed a lower engine knock. I contacted AIM the following business day, 8/19/13. They put me off for two weeks and then told me the engine would not be warrantied. My invoice from AIM lists an 180-day guarantee-- it has not been 180 days since the order was (finally) completed (6/27/13). I would like AIM to adhere to their guarantee and either refund my money (shipping their engine back at their own cost, as they have already wasted a CONSIDERABLE amount of my time and effort) or replace the defective engine with an appropriate working one. I have been very patient with this company and have been rewarded by being ripped off.