Most duplicate payments happen either by a duplicate subscription set by the client or when a client has forget and paid the invoice manually while also having auto-payment enrolled. If your account received an overpayment, our system will automatically store this overpayment as an account credit balance. You can at anytime open a support ticket and notify our Billing team to help you identify what caused this overpayment in order to fix it. We can either refund the credit back to the payment method used or keep it as credit balance for future invoices.