Pathetic service

On the 10th of March I requested a settlement letter from Mobicred, paid the amount listed on the 12th. Requested my account to be closed and till today my acc is still opened. I am being told I used an incorrect ref number which is the same ref number they gave me. Everyday is a different story. Anything linked to RCS is pathetic. I want my account closed at the end of the day the money is in their account incorrect ref number or not. The account number I paid into belongs to Mobicred.