non-competence

i took out a contract with vodacom at the fourways vodashop in 2012. i paid every month until my 24 months was over. my contract expired in July 2014. i was surprised when my bank accont was debited in August 2014. i went to the store to enquire and they told me that i have to cancel the contract. i did. to my surprise, i tried taking a phone from vodashop on monday to find out that my account has been handed over to the legal department. i was shocked because after i cancelled the account no debit order went through. the legal department told me that i owed vodacom R617. 40. vodacom staff is ***********. firstly i was never told that i had to cancel my account after 24 months. i didnt complain and i just paid it. but now i am ****ed because i have paid the 617.40 which i dont even know about. i was never told at all about the amount i still owed and i never recieved any airtime or sms from them in that period.i never recieved any communication from them to tell me about the amount owed, no email, no sms no post. i would have paid it long ago without having my name on bad debtors lists. i am so disappointed in vodacom. im never going to use it again because they are dishonest