Stripe is keeping my refund fees for OLD transactions

Like others here, I had been grandfathered into Stripe's original pricing terms, but it suddenly came to an end with a generic email announcing the termination of this plan within 30 days in early March. While I was able to get them to push the transition to Sept 1 due to COVID, I still have a lot of existing transactions, including from pre-March, that could be refunded, since I am in the travel booking business where the service isn't rendered until months away and many trip have been postponed to later this year or 2021. Stripe thinks it's ok to unilaterally change pricing terms and retroactively apply to older transactions. I strongly disagree. Isn't this unethical if not illegal?? Losing the transaction fees on refunds could make the difference in whether our travel company survives this pandemic, and I need the fees returned so I can pay the customer their 100% refund they deserve (per our terms with them). I want to switch to Square or another payment processor that still returns transaction fees for refunds, but Stripe should still do the right thing and abide by the original terms at the time of the transaction. And offering a future credit isn't sufficient since it keeps me hostage on their platform and makes it challenging to issues the full refunds to the customer.