Telkom and Cell Direct

My wife had a two year contract, upon expiry, she was called by Telkom Mobile Agents, Cell Direct. She renewed her contract but was now being billed an extra R359 for 1G per month. She did not consent to this in the first place. Then the service problems started. When she went to report to Telkom mobile office in Southgate (after having called the Call centre), they told her case has been opened and was given a case number. She then received a bill for R690