Not a happy chappy!

I have a contract with MTN for years. My contract is coming to an end and I get a call stating that I need to take some subscription or they will recycle my number. I have been paying my premiums every single month without a miss or delay. Now my contract is coming to an end. Why do I still need to take some kind of subscription? I do not understand this? I have asked the consultant I spoke to was absolutely rude and did not want to hear what I have to say. I do not want a subscription. Why am I forced to take one? I asked him to get his manager to call me and I am still waiting instead I am getting a debicheck from my bank to authorize an amount of R319.where as the consultant advised me initially it would be R119. Also again why do I need to take a subscription when I do not want to. Can someone call me and advise me on this as I am really not happy about the service received at this point.