Dom in Edmonton

Purchased 3 windows and one door. The windows are triple glazed and have sliders. During a cold spell noticed a significant draft from one window. The draft comes in from the sides of the slider and also from the bottom of the window. Mentioned this to the service person when he was here trying to fix the window on the door; was told 'this happens when the wind blows from a certain direction as wind comes in through the drain holes at the bottom. Really??? What good is the triple pane if the window is designed to allow drafts depending on the wind direction? Walk to the next dealer - don't bother with these. When you call for more than one fix, they start looking for things they can blame on you.