On Sept. 9th we received the weekly deals email that said we could get 500 bonus miles AND a free weekend day renting National Car. We tried twice (once in Virginia and once in California) to have the contract ID for the free weekend day entered when we rented...both to no avail. We were told both times it was an invalid code. Has anyone had success (or like us a failure) with this promotion? I assume I complain to National, right?