What should I do if my customer used SWIFT with my local account details?

Obtain the transfer receipt and check the payment method the bank actually used. Local and International SWIFT instructions are not interchangeable, even when both involve the same currency.

Send Support the receipt, invoice and the instructions you gave the customer. Explain that the payer used a different method from the intended route. Ask the customer to tell its bank the same thing so it can check the transfer.

Do not promise that the payment will be accepted, converted to the correct route or appear automatically. For a future transfer, share one complete confirmed instruction set for the method being used. Do not ask for a second payment while the first one remains unresolved.