Originally Posted by
bemis
You didn't mention what status tier you had - only President's Club has "Guaranteed car up to a full size with confirmed 24 hour advanced reservation". If you're lower tier status, they do in fact know how to take reservations, but they don't actually know how to hold reservations, which would really seem like the most important thing.
Having a car for your reservation is a top-tier status perk at Avis, not a baseline expectation.