Accident happens, don't panic. I will suggest to pay again the amount as the receipt has a barcode with serial no that IRCC use to verify your payment. In the meantime try to recover the email address, and later ask IRCC to refund you the amount or ask your credit card company to cancel the payment (You can do it when your credit card statement is available). From application guide:
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Overpayment
If you pay more than the fees needed for your application(s) we will start processing your application, and send you a refund as soon as possible.
Note: You don’t have to ask for a refund. It will be done automatically.
Note: If you’re eligible for a refund, we will issue the refund to the person indicated on the Payer Information section of the receipt (paper applications). If there is no name indicated on the receipt, we will send the refund to the applicant."