Billed double than previous account, **** service

We were on the 4MB uncapped ADSL line for R770.00, then Telkom phoned and offered a package of R 600 for the fibre optic line, 10MB/ps, 50gig and the special stated till 1 March, we will get 50Gig free. Our usage does not even get close to 30Gig. After we paid the 18th of January 2016, we get billed for February almost double then what we use to pay. We have contacted Telkom, waited almost an hour for someone to respond with a huge attitude problem. Then we did the online communication tool and the person just disappear. Why does Telkom remain so PATHETIC???