I just received IC-BK08 today which is a trifold keyboard 

I have already charged it for a long time and waited until the red light is off (meaning it's charged) 

Then I connect the keyboard to my iPad and switch off other nearby Bluetooth devices 

Only keys on the left side (left part of the trifold keyboard) are not working at all!!

But the keys on the middle and the touchpad are also working 

What happened??? 

And how long I have to fully charge the keyboard? How many hours can I use it?