If it is indeed a GMC Dinali, it is advertised as a 21 speed Road Bike. (3X7) If it is not per their National advertising I would get it straightened out. A full refund may be in order.
Bear in mind that a decent road bike, used in good condition, generally start at $300 or so and go up steeply. I have been looking for a couple of months. Used bike prices are going up like crazy, at least locally.