Overcharged and unable to get a refund

I app**** online through the eHome Home Affairs website for a passport renewal 2 months before it expired. I was incorrectly charged a an additional R400 penalty fee, which when I queried it I was told I could request a refund. When I went to process my passport application at Absa Tower in Johannesburg I was told that although the penalty fee was incorrect they would not be able to waive the incorrect penalty fee.