Soaked chickpeas overnight 12 hours not plump
Chickpeas can get old, however, after an overnight soak, though they may be hydrated they are still not yet cooked.
That means they will still be firm, possibly very firm. 

Rather than trying to guess at this point whether or not they are old, just cook them to instructions &amp; see how they come out.
It's really not that easy to tell old beans/pulses before you cook them. Even if a bit old, you can often cook them down given sufficient time.