TELKOM BAD BAD SERVICE

We got the October internet data spesial deal 40GB day and 20GB night from Telkom but never get to use our data because Telkom steels our data every day 3GB or 4GB disappear for no reason. We have been goving in to the Centurion brance every month with the same result complain logged then complain resolved with a promise that we would get credit with the missing data but never do. Now jet again icase number ***7 that was supposed to be resolved on 12 June 2019 but not resolved like Telkom told us as we have no data and we came not do our work for the rest of this month. HOW DO I CANCEL THIS CONTRACT WITH TELKOM.