Ghost number billing by Vodacom

I ported all my numbers to MTN recently. My contracts were past their term. Vodacom created a ghost number that they are billing me for asserting that I never cancelled my contract with them.

I reported an incident of a ********** number with their office and they were unable to inform me that they created the ghost number at the time. Only on my follow up query a week later with no response did they inform me of this ghost number.

They want me to speak to cancellations. Billing me for a ghost number I can never use seems like theft to me.