I looked up the nutritional information on Quizno's website for a sandwich that had mayo, there's a button at the bottom of the screen for the food items that says "show nutrition info" and figured the pts. for the dressing for a regular sandwich and it was 6 pts. The large was more than twice that for the dressing. For the large sandwich (a chicken club) the dressing showed as 620 calories and 68 grams of fat. Maybe that's why the book said 21.
Don't beat yourself up for things like that, but use it as a learning experience.
http://www.quiznos.com/menu/subs.aspx Go to their website, especially if you eat there often. Look up what you normally get, look at other items and see what might work better for you next time. It's all about learning how to make better choices.
Best of luck to you!
I don't know what they put in their mayo or how much they put on a sandwich, but