When you buy something with your Apple ID, your payment method will be charged either at the time of purchase or within a few days.
Some purchases might be grouped together onto a single charge, so if you don't recognize a charge, check your purchase history. Purchases are grouped by the date that they were charged to the payment method that you have on file. If you don't recognize a purchase on your statement, compare your purchase history to your statement.
If you see a charge on your card or bank statement for a purchase that you didn't make, contact Apple to report unauthorized charges. Only Apple has access to your payment information, so only they can issue refunds.