Unauthorized debt order

My contract ended, somewhere last year July, I then kept my account up to date with the my UIF money, I skipped about 2 months, and got another job. I then called the Telkom Billing department to make arrangements, they then said I need to pay 2k immediately or my contract will be canceled, I then told them I could not afford to pay it immediately. The end of the month they then debited a 1k,I called again today, to make arrangements they wanted R1k upfront again, I said to them I can not afford that much. But they will be debiting 3k end of this month. They said that I can not make arrangements without paying