Your post doesn't quite make sense; were you trying to obtain an award ticket, or a paid ticket? It sounds like the former. You should have been given the opportunity to ticket immediately; if the reservation was held and not ticketed, that was your choice. It was your responsibility to call back or visit a United ticketing location before the hold expired. If you did not contact United in any way before the deadline, the reservation would be considered abandoned, and automatically canceled--there is no automatic ticketing, ever.

Most domestic reservations can be held for 24 hours (fares are not guaranteed). Once a ticket has been issued for a paid reservation (there is no such thing as "hold with a credit card"--there is only "purchase with a credit card," and this means your credit card has been charged), you can obtain a full refund within 24 hours.

In any case, all UA flights out of OXR are 30-seat turboprops, and there just aren't that many seats available ...

See what you can get out of BUR.