Poor service

I paid up my account already last year but game is refusing to update on the credit bureau. I have been notified by transunion that game said they didn't receive any payment from me while i have a paid up letter with me and my account was debited with the agreed amount. Now my life is stuck because game depute that i paid them up despite the prove that i have. Please note that this is delaying my process of doing other credit matters and also decreasing my credit score. I wasn't working for 2 years and as soon as i started working i settled their account but now they giving me runaround for the money that i paid. Please sort out this matter urgently.