Small Giant don’t store your email address, so to them it doesnt matter which email is linked to which Google Play account. When you say “Mi-a dat alt id,” do you mean:
A new Google Play ID, from Google?
Or
A new Empires and Puzzles Account ID? And if so, who gave it to you?
I think there was a communication failure between you and them. But they need the receipts to verify that you’re the owner of the account that they’re reconnecting.