Low beams quit working, but high beams still work

Hoping someone here can help me. I bought my 2006 Dodge Ram 3500
mega cab Dec 5, 2015. A couple months later a low beam lamp stopped
working, so I changed both bulbs. Then two months later the other low
beam lamp stopped working. So I took the bulbs back to Napa and told
them what happened. They replaced both bulbs. Well Sunday the
passenger low beam stopped working. So now I'm starting to get a little
irritated. Well i figured I'm going to start doing some research and since I
don't drive at night, I'll try to google and fix the problem before changing
the bulbs again. Then on Monday the driver's side stopped working. I'm
getting frustrated and can't seem to find anything that matches my
problem. Both low beams are not working, however, the high beams are.
Its a dual high/ low beam set up. So how is this happening? The bulbs
aren't burnt out. And if I replace the bulbs the low beams will start working
again. Also, apparently this truck is from Canada and the the headlamps
are always on. I can't turn them off. If that helps any. Thanks