Bridge of contract

<p>I've taken out a contract with cell c it's for a WiFi router with 20 gigs day and 20 gigs night for R400 a month with a with a extra R50 if I run out, for the last 3 months they have been taking round R520 a month I call them every month to question why and what is going on. All 3 times they said they are sorry and have fixed the problem and will credit my account which has never happened I have had enough now. I also feel that they aren't giving me 20gigs as the gigs doesn't even last half a month, I feel cell c is robbing me and won't allow this to carry on.</p>