No replies, debit order error

I ported my cell numbers from vodacom to cell c end of September. Paid cancellation fees and pat confirmed my contracts were both cancelled. Then end oct my account gets debited 1944 from vodacom and ever since i am not able to get a reply out of them, not from customer service or retentions. Today they call me asking for a different person who is apparently a co member of my number???!!! Can somebody please sort this out as a matter of urgency.