Cancelation of contracts

I have been trying to contact MTN for over 2 days on 808 to give notice to have my contracts switched to pre paid at the end my contractual period of 24 months which happens to be on the 27 of April 2015.<br> The waiting times are in excess of 20 minutes and to injury to insult I get cut off each and every time. I am so happy to be discontinuing service with this company as I have contacted them several times already on the poor signal quality in my area.<br> Is this a way to keep your customers paying by not giving them a reliable method to terminate their contracts.