DEBT HANDED OVER INCORRECTLY

I am deeply disappointed that you have chosen to sell your book debt which included an account in my name - THAT WAS A SETTLED ACCOUNT! I paid up my gym contract by debit order and i ws debited for all amounts due. yet my account was not updated and the debt handed over to MBD debt collectors who have been harassing me for the last 6 months. I have provided proof of payment, it does not help. I called Virgin Active and they sent me confirmation that my account is settled, but then why was my account handed over in the first place. I have been a loyal customer of Virgin Active, I will never ever take another product from Virgin Active again.