BAD SERVICE

Hi, i have a contract with cell c and i have queried a few times with them regarding over charge on my account, i took out a contract on a router and i was told that it had a cap on it, however when i got debited and queried it i was told it would be sorted out however it was not cause i am still getting debited extra and it is going over my usage this is honestly ridiculous cause i was told the limit was set and nobody has gotten back to me to have this sorted out so if no one is going to be of assistance i will have this cancelled, even the manage at the store had an attitude regarding this