My contract has expired but service not cancelled

Hello Peter please help me out with this situation, I have a cellphone contract with Telkom that has expired on 14 Jan 2016, I put in a 30 day notice in December and I went back again in Durban 320 Telkom Direct shop to log in another case because no one has contacted me,to find that it was not done,far enough I log in another one on the 06 Jan 2016,Case number:***5 to cancel number ***, this was not done because I received a bill to pay on the 29 Feb 2016 amount of R171.58 because my account has now gone to month to month while on contract I was paying R99, I phoned the call centre to inquire about cancellation they told me about 30 days, and I dispute the amount of R171.58,agent log a dispute case ***0 on the 10 Feb for Refund,and I waited for feedback nothing happened when I phone through they advise the dispute was send to the wrong department,so they will send it to the correct section,I'm not using that line since December 2015 but I'm being billed and I have received a new invoice now of R125 due on the 01 March 2016,the only calls I received was agents wanting to sell new product,where is customer satisfaction in this case,paying for service I no longer need