Need to cancel my contract and no answer!

My contract is expiring in July 2015, and I would like to cancel the contract and convert the number to prepaid, however I am unable to do this as MTN do not answer calls. <br> <br> I am supposed to give one month's notice in order to cancel the contract, but since I am unable to cancel the contract due to poor service from MTN, I'm assuming that this means they will no longer hold me to that requirement of one month for cancellation?<br> <br> In fact, MTN can take this complaint as my one month notification that I am cancelling my contract.