Use QR code to make sure game is linked. 
Enters code for new chainsword skin: 

"This code is for a game that is not owned or linked".
Looks at my account.  Still showing all the SM2 skins I've gotten through PROS.  Still showing my account isn't linked. 
Looks at email from PROS telling me that my account IS properly linked from about a month ago... because this isn't the first time. 
Guess I'll email PROS again so they can tell me everything is working. 🙄