Are you sure the RPi's ethernet cord is plugged into the right port? Some ethernet wall plugs have two different kinds of connections(PHONE and DATA). Try them all, making sure to push the cord in all the way. If none of them work, try installing NOOBS, and install Win10 IoT and Raspbian. If you still can't get it to work, then it could be a problem with the Pi itself. Other than that, I've got no idea what could be wrong.