Totalsports ***** - Changing my store plan without my consent to take my credit!!

Good day, I am a loyal Total Sports customer. Have been for years but I am so displeased regarding service and unprofessionalism I have been receiving from the store and resolution to my issue, i Pay my account every month on time. Total sports has said that collections has changed my store plan to 18 months without my consent. This has now affected my credit and R1500 of my credit has been removed from my account, a total sports employee called customer support but they say collections need to do it, numerous calls has been done to collections and not once has a supervisor or manager called me back as promised. i am unhappy and this is ***** in another way from the store. I want my credit back and this has been a displeasing situation, the Manager of the store is not concerned at all unprofessionalism. Vincent Park Total Sports East London. Please Help! Thank you.