If you have a Costco (or similar) membership, you might want to make the reservation through them. Budget, for one, has a desk dedicated dealing with Costco reservations.
Costco is a significant revenue source to Budget. I know this because I recently had to resolve funny business in LAS. The local franchisee was worthless. One call to the CSR handling Costco on the 800 line resolved everything. It was not a issueof resolving the dispute in my favor..it was just a matter of honoring the price on the printed Costco reservation.