Saying to Choice 'I had 120,000 points and now I have 112,000 points so you owe me 8,000 points is pretty meaningless to Choice. I cannot imagine why they would simply give you 8,000 points.
On the other hand, it is easy to log into your account and see all of your activity for the last year. You claim there were 'a few' reservations made and cancelled. You should be able to easily see and quickly figure out where your missing 8,000 points went.
Choice will be more receptive to I spent 8,000 points on hotel x on date y and you never refunded those points - or they will tell you when they refunded those points. You should be able to easily compare these charges and refunds to your email confirmations.