No cancelling as requested, not porting number

i have two contracts with MTN one expires on 08th November 2015, called on 30th September to give months notice that i am not renewing it, was told a note had been made it would be cancelled, called on 08th November 2015 told to cancel again and to request my number to be ported, was told all will be done and would take 24 to 48hr, it is now 4 days later, no cancellation no number ported, i will now be invoiced and charged for another month i dont want, call centre staff tell you diferrent stories, seems like nobody notes what they speak to you about, i am so angry and feel so violated! poor poor experience! you can never speak to a mangager either! i will not be renewing my second contract when it ends next year, they are quick to offer you products but to cancell it it takes them forever and suddenly nobody can assist!