def METHOD_NAME(self):
    if not InvoicePaymentMethod.objects.filter(active=True, classname='postgresqleu.util.payment.trustly.TrustlyPayment').exists():
        return False
    return InvoiceRefund.objects.filter(completed__isnull=True, invoice__paidusing__classname='postgresqleu.util.payment.trustly.TrustlyPayment').exists()