Got it.
Take away pry angles, mount a heavy-duty stainless-steel rectangle around the opening to the bill accepter.
I bolted 3/8" thick stainless-steel plate to the bill
changer door to stop the Harbor "Fright" battery powered cut-off tools from having an easy go of it.
Encase one
lock in a stainless tube to prevent easy cutting. This will take some work, or you can have it commissioned.
Take away ANY ability to hook a truck and chain to ANY part of it.
You have to look at it as if you were the one to try to break in and you don't care what kind of damage you're going to do, then work backwards within reason.
Also, each
changer model, building design, and installation has its own challenges
I've tried to find a balance between aesthetics and Alcatraz.
Is there a specific issue you're having?