Notice Given - Contract not cancelled!

I have been a patient subscriber with you as a company, but I have reached a level of anger now! I called MTN 808 to put notice to terminate my mtn contract in November 2015. After about 5 different phone calls each consultant telling me a different date as to when I can put in notice to terminate. I managed to get the right date and with this I have put in my 30 day notice. Today (February 2015) I get invoiced again for this number. I am ****ed off with MTN! why is it a struggle to cancel my service AFTER my 24th month period?? I was told my last invoice will be for January 2016. I want this cancelled immediately as you are now in breach of contract. I have provided 30 day notice to terminate. I expect a refund from MTN for this EXTRA month billed or I will be taking legal action against you. I have followed everything by your rules and now I'm ****ed off! I cant wait to cancel my other contract with you! every time I get told a different story and I am now fed up! I will be waiting to hear from you or you will be hearing from my attorney. Money is not the issue, its the principle of the matter!