complain letter to MTN

<br> I Violet Khoza Account no A***<br> Cancelled my contract with MTN via email in May because no one picked up my calls wen i wanted to do it telephonically, every time when i ask for my refund as i have extra money that i have been paying i get no respond i called the customer care line for more than 100 times now, that i want to cancel my contract and be refunded no one is available to help me. they send me airtime every month on the 20th of which i do not want it anymore. can you please cancel my contract and refund me the extra money i have paid please!!! please do not make the strike issue my problem. if this is not dealt with i will be forced to report it to the ombudman.