Bad Customer Service by MTN

I have been struggling to cancel my data contract with MTN . I keep contacting them and they keep putting me through to their Cancellations Department, where my call is never taken. I have sent them an email but thus far I have not gotten a response confirming cancellation of the contract and the debit order went off even though I sent the email prior to my debit order date. I have never experienced such bad customer service from a mobile network.