Tank Assembly problems of the 2010 Volvo XC60

I own a 2010 Volvo xc-60, purchased in sept. 2009. Today, for the third time in 6 months this vehicle ran out of gas due to a faulty fuel gauge. All three times the gas gauge indicated slightly less than 1/2 and the odometer message said "140 miles to an empty tank. Since both my wife and I drive this vehicle it is difficult to remember how much the vehicle has been driven since the last fill-up. I am very concerned that this might happen again at high speed on a highway, at a busy intersection, or at night in an isolated or unsafe location. The Volvo dealership again has the car in for repairs, twice they claimed to have fixed the problem. I have no confidence that Volvo knows what the problem is or how to fix it.