If the purchase was made via an Apple device then you will need to contact Apple directly.  They don’t allow us to handle any transactions from our end.  This link will take you to their contact page -  https://support.apple.com/contact

If the purchase was made on Google, we are able to refund that ourselves in most cases.  In order to search for the transaction I’ll need either the Gmail address linked to the purchasing account or the GPA number that should appear on the receipt. 

If neither of these options are available, like in the case of fraudulent card use, your best option is contact your bank and Google or Apple to get any extra transaction information.  In those cases, we have no way to access the transaction to refund it from our end.