Dead Space 2 Invalid Serial Number

A year or so ago, I bought Dead Space 2 from Steam as part of a bundle. At the time, it downloaded, installed and I played it for a few hours without any issue. About a week ago, I reinstalled the game and received the error a fair number of other people seem to be having - Invalid serial number entered. (I never entered a serial number, nor received one - I assume automatically done). I tried to find a serial number that I may have missed through Steam, no luck. I contacted EA support first, and received a literal copy and paste - word for word - from google of the answer that I already found through google myself before even contacting support (which didn't help). Was additionally told to go through Steam because EA doesn't have visibility of keys issued from a third party, and that games Dead Space 3 and before have been sunset or something like that. 

Went to Steam support and was funny enough, told that no keys/serials are issued, and that I wouldn't be asked for one upon installation. That the game, once purchased is tied to your account, etc. etc. And finally that I should contact EA support to further research the issue for the same reason that EA gave essentially - that they cannot manage keys of a third party.

At this point, I just want to play the game...

P.S. At some point, the joke just isn't so funny anymore.

P.P.S. I get the whole fact that anyone in support googles things generally - it's common... But man, at least try to make it seem genuine.