I have read that it must be returned to the place of purchase.
I do know that Staples would exchange for a brand new one but I don't have one to send back to staples.
You can return an online purchase to your local Staples location. I've done it a few times. If you're still experiencing the light bleed issue, I'd would return it and get one locally from Best Buy. BB seems to have more inventory than Staples.
I also sent my SP back to Microsoft for a warranty repair/exchange. It was turning off when the power cable is unplugged even with full battery. Sent it out on 3/21 and received the unit back on 4/2. It seems to be the same unit as the serial number is the same under the kickstand as the one I sent. It came in a small brown box and another separate box with another charger. Not sure why they sent another charger but I'm not complaining as now I have two to use.