Billing problem unresolved

I sighed up a contact with Telkom Mobile 1 October 2013. The agreement specified free Telkom mobile to telkom mobile calls and free telkom mobile to telkom land line calls for the first 12 months. Telkom Mobile stared billing me form Mobile to land line calls from May 2014. I queried this with customer care numerous times in June 2014 and managed to talk to a manager Tyron Naidu who said he would follow it up and sort it out for me. I emailed him twice with no response. Telkom Mobile did not return to me with feedback on the query, neither did they refund me. I would like a refund for all the land line calls that I was billed for up to October 2014. My contract with Telkom Mobile will come to an end in October and will not renew if I do not receive any feedback on this matter.