Unfair customer treatment

I went to telkom thavhani mall to change my contract number. The assistant canceled my contract by mistake. The Sim went off immediately. The contract was 2 months old. They told me to pay the phone cash, which was 9 thousand something, I told them I can't, I don't have that kind of money. It's been 3 weeks now, they don't call. I can't make or receive calls. My other contract number is also blocked, the reason is that 9 thousand something which I'm owing according to them. I am very much frustrated, no one is willing to help me. 😭😭😭. I did nothing wrong but I am the one suffering. No urgency in the matter. I am buying airtime from my pocket whereas I paid for minutes that I can't use. This is painful, I can't even sleep at night.