Day light *******, pathetic service

Hi I have a debit order of R544.98 that goes off every month on the 25th. Not once did I ever miss a payment since I have my contract but i requested early October to have my debit order changed to go off on the 31st of every month. For the month of October I decided to pay R544.99 on the 30th October using the Vodacom app which reflected the same day and now I am being billed a penalty fee which is definitely on I made a payment a day before my debit order went off Vodacom has no right to charge me a penalty fee for receiving their money a day in advance. I can understand the penalty fee if Vodacom did not receive my payment at. I want the Penalty fee reversed if this is not reversed I will escalate this matter further and will go to the ombudsman.