Reaped off by telkom mobile

I received my wifi router data(20G) on Sun the 1-Dec, today Wed 4th Dec When switching on my router I received the shocking massage that my data is depleted. This for a router that never has network reception all day at my office, only on for a couple of hours when I get home, and off all night while I'm sleeping. If I must calculate in hours, I can say this 20G was depleted in less than 10 hrs. I phoned customer care this morning, they can't even help me with log sheet for how the data got depleted. Asked them to Quote me for a cancellation, I was again shocked when they said I must pay them more than R1200 to cancel a contract left with one year. Telkom wants me to pay them R139 x 11 to get out of their raw contract. When I asked to speak to a supervisor they said he was unavailable, said he'll phone me as soon as he gets out of a meeting. If telkom keeps theis supervisors in meetings from 08:30 till 11:30 why do we still have so much unresolved problems?