How many miles since the last flush? If it hasn't been flushed in the six years you've owned it, then it's surely high time. Is the fluid looking fairly dark on the dipstick? If it were me I'd try a flush before dumping the car, however I would probably buy a case of Mobil 3309 and do it myself vs the dealer.

Also, those transmissions seem to be finicky in terms of the fluid level. They sometimes want to slip if the level isn't right up to the full mark. Check both the cold level and the hot level.