Call plan

We upgraded our ADSL line and Telkom changed our call plan from an anytime package to a weekender without my knowledge or authorisation. I have been trying for a year to get it changed back to the anytime package. I have called the accounts department numerous times without success and I even went into a Telkom office at Tygervalley. Every time the person assures me the call plan has been changed and when my account comes I see that it is still on the weekender. What do I need to do to get the call plan changed???