The whole point is that everything is in an official ledger, that can be argued over in front of a judge.
Best you can do is say you don’t consent for your data to be sold. Find a smaller bank or a credit union where they have to give a shit about their customers.
Most banks offer bill-payer services. Add your school into your bank system and mail them a check straight from your bank. No need for envelopes or stamps, your bank will mail it for you. You can setup a repeating schedule.
$2 for me to give you my bank account info? How about you hire another clerk to process all the paper checks you nitwits. Obviously only rich saviors running the school district if they don’t see the problem with a processing fee.