Dissapointed customer

Vodacom did not do me well as I have paid my installment via their app on the 28th of March 2024 of which the debit order was supposed to go through on the 2nd April but I decided to pay before that as there is another option to do so. Now they have charged Mr with a penalty fee of R100.88 because the debit order didn't go through and then I called and explained what happened because atleast I have paid but they are telling me that they can't cancel that penalty fee as I didn't call them first to let them know about my payment intention so they can't help me..what I don't like is that even though the debit order didn't go through as planned but I did paid though I don't owe them so why is hard for them to help me remove that fee because I paid and it does reflect on their system that I paid on the 28th via the vodacom App. I am really disappointed to be doing business with them really..