Walk Behind Lawn Mowers

A few months ago I bought a all wheel drive mower from lowes. Worked great.. today I went out to use the mower and noticed that the power to the wheels was weak. It would help me up the hills on my property but now I have to push it up the hell. With the amount of money I spent a few months ago I should be dealing with this. It has a 3yr warranty looking for help on what I need to do. Also out of the box there was no hose hook up with the mower to wash the deck. Please help...