Charged for 3 Contracts yet have only 1

In August i was called by CellC call center offering me an upgrade on a Contract that i had with Cell C, i agreed to the upgrade and requested a number change as my ex wife was using that number which the consultant told me was not a problem, she will need to cancel the contract and give me a new contract which i agreed was fine, a week later i called the call center and wanted to do sim swap as i had a prepaid number which i wanted to use as the contract number and the Call Center advised that a fee will be charged to do the sim swap. when my debit order went out i checked the statement and found that i have been charged for 3 contracts instead of 1 i have 1 contract which i agreed to and 2 prepaid numbers but i am being billed for 3 contracts, i then reversed the debit order and contacted customer care several times and each time i get told the matter will be escalated have also emailed Cell C and only to get automated response that i will be contacted in 24 hours but to no avail. i have last week been contacted by debt collectors last week on behalf of Cell C looking for payment Cell C needs to correct urgently as i will seek the Legal Route if i am forced to and will use the Guidance of Consumer Protect ACT