********** debiting of my bank account

I cancelled my cellC contract on 29/12/2015 due to emigration and made the cancellation payment of R5529.71. I received confirmation my contract was cancelled via sms and I was a prepaid customer. On the 29/02/2016 I was again debited without my consent R4899.13. Can someone please explain why I was debited, who authorised it and when I will receive my reimbur*****t? Please note I am no longer in South Africa and I am only keeping my bank account open for YOU to reimburse me. I expect this to be made a priority!