Paid up letter.

I had an account with RCS in the past, then went under Debt Review and now have paid the account off. I then called their offices numerous times requesting a paid letter but they are taking me from pillar to post. Have spoken to the lady at the Debt Review dept and she assured me that i would get the letter within 48hrs and that has turned into 4 weeks. have spoken to almost everyone at the RCS office but nothing has happened. Their customer service needs working on, they do not care about us.