Once a payment is successfully completed, the funds cannot be reimbursed through the GoCrypto system and the refund must be made by the merchant.
Among other reasons, it is impossible for GoCrypto to transfer the funds back because of the nature of certain crypto wallets (the transaction can be a multi-signature one, transfer made by users from exchange, or custodial wallet). Furthermore, the cryptocurrency exchange provided by GoCrypto is instant, and the refund would be subject to exchange volatility.