Harassed after membership cancellation!

My Membership ***. Father's membership 9a***(?). I cancelled my vitality membership last year and was told that my gym membership will automatically end. I was hence surprised to receive a call in August advising me that I was in arrears and the amount outstanding was R659. This was my father's account which I had been paying. I provided the lady with my account details. She also advised me that this amount included that outstanding cancellation fee, and also promised me that this matter will be closed. My account was promptly debited on the 14th of August. I then received another call telling me that my own account was in Arrears, and that I owed even more money on my father's account! Advised I will settle my account at the Southgate branch and take proof of payment for my father's account settlement. Southgate told me that their systems were down and that I could not make a payment however, will investigate father's account & revert. Never contacted.Settled my ac.Today I received an sms from MBD INC - called them - an amount of R700 was still outstanding, membership 9a***(how?). Both accounts have been settled(proof provided), including mine. Y am i being harassed