I find Dollar to be the worst offender in this group. Sometimes, it also seems to be a bad combination of airline and car rental company (i.e., Dollar w/NW). I was able to get most of the miles due, but only after extensive calling. Dollar's frequent flyer desk number is 1-800-800-6080 (but I don't have any of the fax #'s you asked for). Needless to say, I won't rent w/Dollar again.

Good luck to you!