Vodacom Hostage

Vodacom contracts is an ******ion trap. My contract ended December 2017, so the contract says that my contract will continue on a month to month unless I cancel the continuation. December I cancel the continuation and only 13 February I get a confirmaction that my number is prepaid. Today I get a letter of demand for R5000, so I called the call Centre and Maria Sangweni tells me that I cannot cancel the continuation of my contract if there is an arrears, which is for January, and if I want to cancel I must first pay the R5000 otherwise they will blacklist me and block my device, even though I have not received the contract’s airtime or data since December. Basically Vodacom is holding me hostage, I cannot exit the obligation of the contract amount, unless I pay the R5000 while I have a prepaid phone. Plus she could not confirm not confirm what the R5000 is for exactly, the amount is even more than 3 months out of contract amount, even though my services ended in December.