Fradulent deducation of my account

I have had a 2Gb per month data contract with Cell C for the last two years which I cancelled in January 2016. To my shock this morning, I learned that my account has been debit R2930.06 for data usage. Which is improbable considering I last used the data during the first of January.<br> <br> After speaking to a Cell C call centre consultant, I was told that that amount was accumulated on one day of data usage (06 January 2016). Madness<br> <br> After being a customer with Cell C for many, I have had it. Disgusted