MTN ****py Service

I have now phoned MTN on 4 occasions over the last 3 months and have send e-mails and have send a message on their website to get my MTN contract switched to Pay as You Go. A week back they insured me that it is definitely done, and now again today I see that a debit order went off from my account again. I even got a sms to say welcome to MTN Pay per second price plan but I still get debited.

Seriously how many times must I phone MTN to get something sorted out and why do I still get billed if I receive a confirmation sms to say that it has been switched. I am getting seriously ticked off with this ****py services and even if you send an e-mail or leave a message on your website no one ever gets back to you