Cruze transmission problem (Part 17)

Whole taking a break halfway to the Gold Coast on our Christmas trip the reverse gear in my automatic 2010 Holden Cruze wouldn't engage. The car would only drive forward, but wouldn't go beyond 40 km/h. I arranged for roadside assistance and towed it to a nearby Holden Dealer where it was determined that the transmission was malfunctioning. My options are to either replace the transmission for approx. $4100-$4500, or replace the entire gearbox for $4800-$5000. Replacing the entire gearbox transmission with a two-year warranty. I am told it would not be ready for almost two weeks. Is there anything I can do about this now? I know the warranty has run out, but my car only has 42,000 km on the odometer and should not be having such problems.