PATHETIC SERVICE FROM CELL C

I took a data contract whereby data was supposed to be loaded on my prepaid number and instead my sim card was changed to a data sim, had to cancel the contract since I was told it couldn't be fixed. The next thing I know I am being debited and being told that I owe and yet I never used the services. Now I'm being threatened that I must pay or else.. I'm fade up with Cell C I need them to clear all outstanding monies cause I don't owe them a cent and then I will port my number.