Vodacom Making it Impossible to close contract

I opened a cellphone contract with Vodacom in December of 2012. The contract was to run for a period of 24 months. Up until 2014 December, the contract had been paid up. I also had another long standing contract with Vodacom on which I took out a new phone in 2013. <br> <br> In January 2015 I started to experience some difficulties in paying for the 2 contracts and a Vodacom collections staffer contacted me to make an arrangement to pay the account and I paid and made it very clear that I want to close the contract that had run its course. She then transferred me to someone else, and the phone rang unanswered for a while (maybe 30 mins) and I have been having difficutlies closing the contract since. I tried several other times to get through to the call centre to no avail. <br> <br> Surely vodacom should not still be billing me for this account as I have made it very clear that I do not want to be in this contract any longer, it does not make sense for them to be demanding so much money from me.