Is it unusual to ask for a cleaning during the 1st visit to a dental office?

No, it's not unusual, esp. if you asked for a cleaning when you made the appointment. The last time I went to the dentist, I was a new patient and I specified that I wanted a cleaning, and that's what they did. However, I think some offices will do what yours did, probably just to make extra money. That happened to my husband once, and we didn't go back.