Contact support with the purchase references, dates, amounts, and the reason for the request. For a suspected duplicate, identify both purchases and explain whether your bank shows two completed payments or only a pending authorization.
A support request does not itself approve a refund. Review depends on the purchase and applicable terms; a credit adjustment and a bank refund are different outcomes. Keep using the existing conversation for follow-up. Do not delete the team or send full payment credentials while the request is being investigated.