***** account unresolved and Black listed

In January 2018 one of My accounts was upgraded via telephone without my knowledge to a Red VIP account which is over R3000. something I can't afford. I requested a copy of the contract which is a the phone call (reference number 1- ********** ********** ). That still has not happened. Then I received a Reference number i ********** -6 to make payment and after all this time I received nothing on the ***** account and I was handed over to Debt collectors and I've been black listed. When I go to the store in Cape Town Century City, they say they can't help me Because the account was upgraded over the phone. How do I proceed from here?