American Auto Guardian Wheelz Warranty company denies claim for "Wear and Tear" on engine Arlington Heights , Illinois

I work at a busy auto repair shop, we are the best in our area, keep updated on technology, and do our best to provide the best service in town, at a fair price. I am getting really tired of extended warranty companies though!!! The dealer ones are usualy ok but the used car lot ones are a JOKE. I have this Buick on my lot right now. The folks bought 2 months ago from a used car lot, and bought a basic "extended warranty" for the term of 3 months 3000 miles. Well what do you know 6 weeks and 2000 miles later the engine is knocking. Well the warranty company says the customer has to authorize RDI(remove disassemble and inspect) so they do. We get the engine apart, and two main bearings, and two rod bearings are grenaded, the other ones are perfect. The warranty company sends their inspector to look at it and take pictures, the next day we get a call that says, well the vehicle has 144,000 miles on it, we are denying the claim as normal wear and tear. Well excuse me, but if you are going to issue a warranty on vehicle that has 142,000 miles on it, you had better honor it 2000 miles later. The inspector even admitted that the engine did not look like it had been ran out of oil, overheated, or any of the other things that would normally void a warranty. Pretty weird though that normal wear and tear would destroy two main bearings, and two rod bearings, while every other bearing in the engine looks brand new. I am getting really tired of dealing with all these warranty clowns, and I wish people would quit buying these stupid warranties and just put their money in the bank.