Sounds like the battery is in a bad condition. Even with Wifi on you should get way more reading time out of a full battery than 4-5 hours.
You could check:
1. are you sure you've charged it to complete fullness before unplugging it? (You see a check mark √ in the battery icon instead of a 'plug')
2. when charging, does the device stay connected constantly? (Green led light on the top constantly on or not?) There have been some issues with the USB socket on the kobo being loose.
If I were you I'd try a charge one more time, maybe with a different USB cable than you're used to and preferably from a wall charger instead of a computer USB socket.
If that gives you the same small amount of reading hours, bring it back to where you bought it under warranty! Either the battery is bad, or the connection is broken (causing it to not be able to charge properly). Have it exchanged for a new Touch, or (what I'd do) get your money back and pre-order a Glo
