Complaint Review: AAA Japanese Imports Inc.

I purchased a used Mazda Miata 1996 engine from AAA Japanese Imports, Inc. which was guaranteed as a used engine imported from Japan in 'grade A' working condition. Upon receiving the engine, I was supplied with no receipt of purchase, proof of mechanical inspection of the engine or documentation stating this was in fact an imported Japanese engine. The engine was installed by an independent mechanic. The car was driven for 12 days or 315 miles before the engine failed. The independent mechanic concluded this was a faulty engine, with numerous documented holes, cracks in the oil pan, a painted over serail number and in fact had an air intake valve, which are not present on Japanese 1996 Mazda Miata motors indicating it was likely not a Japanese imported engine.I have made numerous attempts to contact AAA Japanese Imports, Inc. and each time was promised a return phone call, which was never made. I have emailed and sent through a via normal and registered mail explaining the situation in an attempt to amicably resolved the matter.