I'm sorry your appointment was cancelled.
I live in Alamance County (which is limited to persons 75 and over) and received the Pfizer vaccine in Forsyth on 1/24.
I recommend that you follow their Facebook page
https://www.facebook.com/FCDPH to learn when appointments slots will become available.
They announce on Facebook (sometimes on short notice), when they will make appointments available (day and time) and how many appointments there will be. Last week, on Wednesday morning, they announced that 1700 appointments time slots would be loaded into the reservation system at 5 pm.
A few days later they announced that 4000 reservations would become available and would be loaded into the reservation system the next morning at 9am.
When you get into the reservation system you are competing against everyone else for time slots. The strategy that seems to work is to go after slots that are less popular so that you'll have less competition. Otherwise, by the time you answer all of the screening questions, the time slot you wanted will probably be gone. Also, you need to type as fast as possible :-)