Appalling Service and lack of urgency for costly customer issues

I'm very disappointed with Telkom. I took out a mobile data contract for which the sales agent in the store misinformed me and told me I would have coverage in areas that I asked about specifically because I knew I would use the internet there. It turns out this particular bundle doesn't have coverage in Queenstown and it took 3 months of running back and forth between Telkom stores (N1 city, Tygervalley and East London) before they told me this. Every other time they just told me to turn on roaming! Their call centre is also useless as the agents would grow tired of answering questions and place me on hold as long as I can before I decide to drop the phone (an average of 30 minutes each time). Now that I know I've been misinformed, they told me to fill out a cancellation form and I'll be charged +-2000 for the cancellation, when I said "but you gave me the wrong info", I was told " There is no evidence of that". So I scanned their cancellation formed and emailed it, and I got an email saying "this email account is full and is not taking more emails at this time!". I was ******* and it looks like I still have to work hard to cancel, what a huge disappointment.