I didn't have my card yet because it was shipped internationally and I'd only reserved a few days in advance of my visit. I brought a printed copy of the email confirmation. The clerk at the ticket desk was extremely rude. She did not believe me that I'd bought the pass because she said the type of email I'd received is not like the ones she had seen. It was King's Day and the main office was closed. She did not have access to a database of "Friends." I offered to buy another pass and just sort it out with the main office next week, but she said, "That is not how things work in the Netherlands." Eventually she gave me two tickets, but she was so rude about it.
Improvements or suggestions
Train the front-line employees on the system and refresh on customer service; make the database of "Friends" (members) accessible to them.