Answer received, and realised I’d given a smidge too much info.
I’d love to say yes, go nuts, have fun. Stick it to em. They deserve it.
But the answer is no. It’s not meant for you and you know it. If you get caught you can get into a heap a trouble and will be forced to pay it back. And this is 100% the sort of thing a bank will close your account for.
I’d suggest maybe contact Eon, explain the discrepancy, have them double check, and make them actually tell you that check for that amount is what they owe you and is rightfully yours. Record it if you can. Then I’d say you’re safe to deposit it.