I'm glad the staff are allowed to be friendly and social when things are quiet. I'm curious why you waited 15 minutes when they told you 5 - i'd have been back there 5 minutes later to check.
I'm not having a go at you, or anyone who has a bad experience at a park, but whenever people are being inconvenienced or provided with poor customer service, the story is always that the staff were laughing or chatting or on their phones. It conjures images like this one:
Again - i'm not saying it isn't true - I wasn't there... However your post suggests the staff were doing something wrong by "laughing and chatting", but I can't say i've ever witnessed staff at any outlet carrying on unprofessionally or outside acceptable limits, for one - goofing off tends to be frowned upon by supervisors - who may or may not be lurking around the corner... believe me they do try and catch staff out, and it isn't worth their job.
By all accounts it was a quiet day - and given that the guy that served you finished for the day, my guess is on the later side of 3pm. When things quiet down, and there isn't much to keep the staff occupied - i'm much happier that they'd be laughing and smiling than standing at the counter like this: