I asked about this when I called and they told me it's because they're so backed up with callers. Unfortunately the only solution is to keep calling and hope you get in. I found success calling as soon as they opened, which is at 8 am EST. Hope your situation gets resolved!
As of last week there were still appointment only. Keep on the website and refresh the browser constantly until you get an option to schedule an appointment. When you get the option you have to be quick. The best times for me were right around midnight and between 10 and 1. If possible, do not limit yourself to the closest office. I am in CT with am office 10 minutes away and I had to drive 4 hours to the NH location. Take what you can get. I was able to get an appointment this way 2 days before my trip after 2 weeks of trying. Stick with it and good luck.
I think if you go on their website they have a contact Email address you communicate with to set up an appointment to go into the office. I believe they're only seeing people with appointments at this point.
Thanks! Your answer is awaiting moderation.