Ask for your money back.
Before the window shuts.

Whoever took the money, which your receipt names. A charge from Apple goes to Apple. A charge from Google Play goes to Google within 48 hours of the purchase, and to the app's developer after that. A charge from the company itself goes to that company.

No. Cancelling stops the next charge and a refund returns one already taken. They are separate requests: do not count on one to do the other.

Only a subscription can be cancelled, because only a subscription renews. A one-time purchase, such as a paid app, a full game unlock or a pack of coins, was charged once and has nothing left to cancel. The only way to undo it is a refund request to whoever billed you.

Because most subscriptions have no refund path. They run to the end of the period you paid for, and there is nothing to request. We publish a refund guide only where a real process exists.

It depends entirely on who billed you, and this is the part worth checking first. Google Play gives 48 hours before passing the request to the developer. Apple's refund page states no deadline. A service billing you directly sets its own, and some deadlines fall before the charge rather than after it.