You don't say whether you paid your date back?

Listen, it was an honest (if dumb, like seriously people, always bring your wallet) on your part, but her being upset is very understandable. My rule is whoever does the asking out/suggests the place to eat(particularly if it's expensive) should pay, but the other party should always be prepared to go 50/50. But look at it from her perspective (I'm making a few assumptions based on traditional gender roles and the fact OP was the one with the crush), imagine getting asked out, invited to an expensive place to eat that may be out of your budget, especially for two people (not to mention guys tend to eat more and have more expensive meals), and then it comes time to pay and the person who wanted to do all these things just happens to have forgotten their wallet. Particularly since it's a common enough scheme. She thinks your a liar and a conman, would you want to give that kind of person a chance to talk you into more bad situations? I'm sorry OP, it sucks that you lost your chance due to an honest mistake. People in the comments, lay off, from the girl's perspective it's perfectly reasonable not to pick up the phone.

Venmo her the cash, say you had a nice time (if you did) and then let her know you'd be interested in doing it again (if you are) and let her know next time she can forget the wallet.

I'd say something like: "Alright, fine. I guess you DON'T want your money back."

el que invita, paga-- the one who invites, pays.

I don't understand how people leave their house at all without their wallets...

You 1000% deserve this. Why doesn't check they have their wallet before they leave the house. Unless it was intentional and you are trying to get pity for them getting angry

for some reason, I read "..going to pay, but when the bill.." as ".. going to play, but when the ball.."