Pay for service not rendered

I had a 24 months contract with vodacom for airtime of 110 every month and I would pay R80 the money was debited on my account every month until 2016 I stopped paying the account because I was paying for a sim card that was blocked since 22 December 2015.I told them to resolve this query they took me from pillar to post.In February February 2016 more than 2 months my query was not resolved.My Vodacom number was ********** 905 it was blocked for no reason before I even stopped the payments now they black listed me on ITC I contacted them on numerous occasions to resolve my line.but no success now I must pay for airtime I did not even use or get. Kindly assist on how to deal with the matter. My numbers are ********** 286