Been there. Done that. There are alternatives that do not involve a veterinarian.
Many safe, humane methods that can be done inside city limits even.
If the vet’s patient is put down, that vet loses revenue.
I suspect the vet said no, because he saw Aunt B as an easy target.
Instead of doing the right thing and putting a suffering animal down, some vets con owners into spending (wasting) thousands of dollars.
All the while - the poor pet suffers.
And I’m a “jack ass”? Hoo boy.