Points may never expire, but accounts can be revoked for a variety of reasons set out in clause 4 of the T&Cs. None of those identified include account inactivity, most all relate to fraud or other such activity (failure to pay hotel bill). There is also a category of "active member" defined as someone having account activity within the past 12-months (of any change being proposed to T&Cs). Check out clauses 4, 5 and 6 for details.
Curiously, the T&Cs also say PC points have no cash value. I don't know if this is so these don't show up on the ICH books as a liability. Most FF program miles are logged as a liability on airline corporate books because at some point they represent seats that must be accounted for.
In any case, I don't understand why you don't just contact PC to determine the status of your account?