You seem to be overreacting a little here.
The age of the device is irrelevant, it's still brand new in box.
If you'd done your research prior to buying you'd know the model and spec hasn't changed since 2011 so the stock could well be that old. If you want something hot off the production line, then buy something that's only just been released.
Your only actual complaint seems to be the battery life, and the fact they haven't responded to emails about it.
I would suggest you call them on the phone, or write to them via snail mail, you are more likely to get a response.
Also while I agree that the battery life does sound poor on your devices, 3 - 4 days does not make them at all unusable.