membership fees dispute

I requested for my son's membership to be canceled and was advised that i need to pay a pro-rate which i did ,couple of days later i was told i am in arrears and i queried with the team and i was old they credited my account instead of his. That neve happened and i paid the outstanding amount instead the following month 2 months later i am told i am i am in arrears again think virgin active is trying to **** me and i just need to cancel my memberships all together