also it wasn't a $70 part that destroyed your engine... it was an $11.66 part that destroyed it. a single SMP injector from rockauto for our vehicle's is $70
looking again at the full listing, it says 2 reviews but those were just people who left a star rating, not a single person actually wrote a post purchase review using words.
I have purchased many parts from amazon website but it needs to say ships from and sold by amazon.com.
have you tried going directly to the seller? if they don't respond, file a complaint against the seller through amazon.
you might even be able to file a complaint against the company through the BBB. some jurisdictions might have small claims court for this sort of thing? I remember a guy took the auto parts store I worked at to court over an oil filter we sold him that apparently damaged his engine after installing it.