Increase debit order with no notification

On the 27th December I received a bank notification of R 262.36 deducted by Cell C from my account. <br> The only contract that I have with Cell C is the 2 Gig Data bundle for R 99. I queried this with the staff at the Pietermaritzburg Cell C store and they informed me that the discount for the 2 Gig data package no longer applies once my contract has ended. I cancelled my contract immediately in January 2015 after consulting the Cell C store.<br> The reason for my frustration is that I was never informed that the discount was no longer applicable and or my contract had ended (Mid December 2014) but instead need to pay triple for December 2014 and January 2015.<br> If I was informed by Cell C that my contract was up for renewal I would have signed a new contact to continue the R 99 data contract that originally brought me to Cell C, but instead have to pay R 572.36 (equivalent of 5 months data contract at R99) in two months because of no notification from Cell C.