Proving ownership of games purchased via Steam

It's been 5 years and this is still a problem.  Im dealing with the same support options right now and I'm directed to complain to steam and not here that its not their problem.  They can come out and say you should have bought it from us, but that's what they are doing.  A way of scamming and cutting out their competitor making it my (the customers) problem is a heck of a business and ea is working on their masters.