RCS Game ruin my life by poor quality of work.

I app**** for credit in another institute, which was very important credit, institution declined my application said I have overdue RCS Game. When I opened my credit report I found that I had two game cards and one is overdue. Called game to inquire, They told me the overdue account is not mine, it somebody else. How did it get to my report, said it mistake. I asked them to at-least send me a letter, so I can send to the other institution so they can give credit and this urgent. This was Monday, they said the turn around time is 48 hours. When called them 3rd time. No one has record what I am talking about. I had to explain myself again. My whole life dependent on the credit. I am stressed and disappointed.