Why is my Dakota GPS giving wrong direction

Why is my Garmin Dakota 10 global positioning system (GPS) misleading? I recently bought a Garmin Dakota GPS device, but instead of guiding me, it is misguiding me. Whenever I switch on the GPS device, it will show gathering information and the initial information like current position is always accurate, but immediately after asking for direction, the information I got was sometimes wrong. More than two occasions, I have found myself in an entirely different place than intended.
