Try a clean reinstall of the client (or install enhanced client) to see if the gump shows (I'd do the enhanced client, personally). IF that doesn't work, contact a game master or EA support.
IF your account predates AoS (and has had serious amounts of downtime), there was a bug/exploit at one point, around the time that Vet rewards first came about, that allowed some people to claim many more than their allotted numbers of vet rewards. As a result, those accounts have NEGATIVE numbers of rewards available, until such time as the number of rewards gained offset the extra rewards that the account claimed. Some such accounts are rumored to have been so heavily exploited for the extra rewards, that it would be next century before they become eligible again for vet rewards, even at 2 per year after 84 months.