Reluctant to Cancel Contract

My Cell Phone Contract for cell *** expired on 19-May-2015. Tried their call centre (808), which you have to wait for hours for someone to answer, sent emails to customer care from 06-May-2015 ( ref number: ***4), sent a complaint on 26-June ( ref number: MTN REQ:***), no response from complaints and to date MTN does not want to cancel my contract. Whilst my contract has expired my monthly bill increased from R259 to R314 which I paid for Jun. Now I have another bill for Jul. MTN does not want to cancel my contract but want to bill me. This is *****ing. Spoke to a person at the 808 number on 17-Jul and she advised she cannot cancel but my call will be escalated. Why, the contract expired, pathetic, poor , and... Sent another email to CC and again get a response such as we apologies for the delay,...Nothing about cancelling my contract. Frustrated and tired!!!