Worst service ever experienced!!

I had an Game/RCS account which was handed over to VVM for collections. It was paid up in October 2014 and I requested a paid up letter which I was told I had to pay for and I did. I never recieved the paid up letter and 1 year later, I get a call from a different agency telling me the account is in arrears. I have contacted both RCS and VVM for the paid up letter and keep getting a different story from both. No follow ups are done as promised, each agent gives a different story to the last and I am still stuck without the paid up letter. I want this resolved immediately!