I missed payment on my subscription in May,and recently made payment of R264 which they debited from my account end of August

I missed payment on my subscription in May,and recently made payment of R264 which they debited from my account end of August.This past Saturday I paid another R264 via a link that was sent in small form. On Sunday I get a text that I must pay R955.I have not used the service since June and suddenly I owe that after making those 2 payments how????? I tried calling their Support or Customer service line but I was unsuccessful. The line kept hanging up.This is unacceptable for a company this big to not have alternative contact tools for its customers to use. I need an agent to call me so I can settle this matter.If HELLO Peter can assist I'd appreciate it.