Still being billed after contract was cancelled

The service from Vodacom is absolutely disgusting. I received notifications from Vodacom that my account is in arrears, I cancelled this account 2 MONTHS ago. Subsequently after cancelling I also did not receive any airtime on that number and assumed the account was cancelled after I made use of the telephonic contract cancel line and I also spoke to someone from your call centre because they wanted to sell another contract to me, they wanted to make sure I want to cancel and I told them 'Yes'. Now I am being told my account is in arrears and I need to pay. My account was settled before I cancelled the account, so I suggest that you sort your stuff out. <br> <br> I am not going to phone your useless call centre again. Please can someone competent phone me to sort the problem out, someone that actually knows what they are doing?