Contract cancelled and confirmed by MTN but....

In 12/2014 I advised Mtn that I wanted to cancel my contract. My cell no is ***. I was informed that my contract expired on the end of 22/02/2015 (#***), so I could only cancel it then. In the mean time, the phone appeared to be blocked as I could not make calls and never had any airtime, although I was paying for it. <br> <br> I called and they promised to investigate. 31/01/2015, I was then told to change the sim card into another phone and the outgoing call barring should be rectified (*** from retentions) and it would work and the airtime would reflect. I did this in February 2015 and it worked. <br> <br> 02/02/2015, I emailed retentions department and logged a request to cancel my cell phone contract on the 23 February 2015 and have the number ported to a pre-paid number. I received confirmation that they had received the request (***). <br> <br> Sadly to date my cellphone contract has still not been cancelled and today I have just received another account for for June 2015.<br> <br> These are all my reference numbers - Customercare - #*** - 30/03/2015, 07/04/2015,<br> -Retentions - #***,#*** - 20/01/2015, 31/01/2015, 02/02/2015, 29/04/2015<br> Please help me!!