Struggling : Looking for Paid up letter

I was on debt review and paid up the full amount on the 9th of April 2015 already. I have send an e-mail to the relevant department with the proof of payment on the same day. I tried to contact the debt review department numerous times on 4 numbers I was given the phone just rings. I tried to contact the customer care and they just give me the same numbers. I really need that letter to send to the debt review people. I did not have any trouble with the other places. This is my last resort. I am really disgusted because it was a lot of money and paid it immediately. I need that letter Edgars!!!!