“ They said I shouldn’t just walk away.”

I have to agree. Did you at least consider the “run like hell” approach? I say that after considering who appears to need the other more. Since if you had remained you would be the one paying with each submission, the price for you leaving seems substantially less than for staying.

But perhaps a nice note to thank your publisher for the two awards you won (thus far) might be “appropriate”?

Thank you for this example of integrity coming first. (Especially welcome in the Age of Drumpf.)