Despicable service

Really bad experience. After 4 years of my debit order coming off on the same day, it suddenly changed without my permission, seems like their system got covid 19, because it was just after lock down started that only 1 of my debit orders got changed. I proceeded to ensure that the money is in my account the day the would send a text informing me to do so to avoid bank charges, but then around the end of October or beginning of November, I go into a branch to change it back. Low and behold, I get another text at the end of November to ensure the money is in my account early. I try to call, after an hour of hold and speaking to the wrong department, my airtime runs out, at this point I have spent money on bank charges for the first failed debit order, traveling to and from the branch to change it, as well as airtime to get hold of somebody who can help me, as well as bank charges for the second failed debit order because this time I couldn't pull money out of thin air to have available for them. I also logged an electronic complaint, to which I have had no response to this day. Then I go back to the branch, only to be told about some system that's taking the money early, why now? Why only for 1 debit order? No further answers, just that there's nothing they can do about it because their system shows that the date was changed. So how to proceed?