Im currently experiencing the same bug. This post is 8 months old, has any solutions been put forth? I really dont want to lose my account just to buy coyns.
Im having the same issue, I want to buy coyns, but the game refuses to allow me to link my account to buy them..I dont want to throw away 1600 hours of game play and a dozen blueprints that you cant get anymore...any help would be appreciated.