(36)This Directive should lay down rules for a refund to protect the consumer when the executed payment transaction exceeds the amount which could reasonably have been expected. Payment service providers should be able to provide even more favourable terms to their customers and, for example, refund any disputed payment transactions. In cases where the user makes a claim for the refund of a payment transaction refund rights should affect neither the liability of the payer vis-à-vis the payee from the underlying relationship, e.g. for goods or services ordered, consumed or legitimately charged, nor the users rights with regard to revocation of a payment order.