Andrews - I think you are confusing this with not being recommended for certification if you have an open nonconformance in your assessment.
All nonconformances found in your assessment audit have to be closed before your registrar can recommend you for certification.
If you weren't allowed to have any customer complaints, we would all be looking from the outside. As a matter of fact, I think an auditor would be very critical of a company who had NO customer complaints. To me it would indicate they are not listening to their customers and ignoring their feedback.
Dave