If swiped twice I would expect two $27 charges. A single $54 charge suggests that the lounge attendant filled out the form incorrectly -or- it was processed incorrectly at Priority Pass. Some versions of Priority Pass do charge $27 for each member visit. The attendant does not know the details of your membership but if s/he recorded it as "two guests" rather than "one cardholder plus one guest" the billing could be incorrect.