trying to cancel my contract

I was told by the Pinetown branch to phone the accounts department in order to cancel my contract which expires at the end of March 2015. I have been trying since 24th February to get through to the relevant department to no avail. Just today my cell battery went flat twice while holding on listening to their computer generated messages. At no time did I hear a voice telling me to leave my cell number and one of their staff would phone me back. I can see that by the time I get through to the accounts department I will be told it is too late to cancel the contract. Should this happen, I will be going to the newspapers with this problem. Please somebody, tell me how to get through to the accounts department.