Unauthorized Debit Order Changes and Poor Customer Service

I have a loan, with a monthly debit order that goes off on the 25th of each month. In December 2020, instead of the 24th, directaxis helped themselves to this installment on the 16th without any notice or request for permission. Since this was over a week before I was even paid, they basically cleared out the last funds in my account. I sent an email asking who gave them authorisation to change the date and to this day, despite my regular follow ups, nobody has bothered giving me an explanation. I cannot wait to settle this loan so that I never have to deal with this company again. Their customer service has always been pretty bad, but this takes the cake.