End of contract - no feedback

I am at the end of my contract and notified the customer services per email on 10 April that I want to end my contract, but I want to keep my number because I will use pre paid air time. <br> I received a ref. no. and they will come back to me within 5 business working days. I have forwarded the email with the ref no a couple of times, but everytime I get the message to wait 5 working days. <br> Your 808 number is also not very helpful. The fourth time that I phoned them, a person helped me and gave me a new ref no, but with another 3 days waiting time. On Thursday Dimpho at Cradlestone Mall helped me to send an email to her supervisor, but I am still waiting!<br> I am a contract customer from MTN since April 1996, and this is the service I get. MTN, WHAT must I do?