Penalty for Changong Payment Date

Telkom added R200 to my bill because I changed the debit order date. The lady I spoke to when changing my payment date did not advise that there would be costs added when I change my payment date. Another gentleman called me and advise that he cannot give me the lady's name or the reference for that call because "Telkom does not allow it", his call miraculously went mute when asked for HIS name. He refused to give a reference as well. I fail to understand why there would be a penalty of A WHOLE R200 for changing my payment date. I am disappointed, most especially because I have been a loyal customer for years.