Stilled being billed after prepaid request

So the 29/02/2016 I contacted Vodacom in respect of moving my contract to prepaid after it reached maturity of 2 years at the end of March 2016.<br> <br> However it appears I will STILL be billed at the end of March on the month to month basis. I requested that I be made prepaid, NOT MONTH TO MONTH.<br> <br> You guys confirmed telephonically and via twitter, now nothing has been done.<br> <br> This CAN NOT be this difficult!!!