Stuffed up my debit orders - deducted revolving loan instalment thrice in one month

How on earth can my account be debited thrice in April for a Revolving Loan debit order??? Initial debit date was the 1st of every month. I have been struggling since November 2023 to change it to my salary date. On the 3rd March - new debit date was changed to the 21st of each month. Revolving loan department did not update system on their side and then debit order went off twice on the 22nd April because according to them my account was in arrears and put on hold after I disputed an incorrect debit order which they not only debited the instalment amount but for the interest and monthly fees too - on the incorrect date. I am yet to receive an answer as to why it was even debited twice on the 22nd of April????

HOW ON EARTH!! WHEN MARCH AND APRIL DEBITS WERE DEDUCTED AND PAID!!! So again TODAY 3OTH APRIL - my account was debited again - why are they still debiting my account on the 1st of the month - I'm assuming they will be taking for interest and monthly fees AGAIN!!! Which will result in my account 'going into arrears again"????

This has been dragging on for too long now and I can never get hold of the Revolving department when I call. I am being sent from pillar to post with no solutions. They are quick to phone and make automated calls for accounts to be paid immediately... When they stuffed everything up on their side. My accounts were never in arrears, and they are yet to fix their ******* and own up to it. I would like my money back immediately!!!! Fix your mess!!!