What the parent meant was "after you paid the bill". It's hard to go back later and say the charge was fraudulent after you received the bill and opted to pay it. In theory, payment = acceptance of charges.
Theory doesn't matter much here. Especially not with automated debiting of checking accounts to pay the balance or some amount of interest or a combination of those.
As a customer of the card company you have the right to dispute charges as far back as you want, whether they'll honor that or not is a different question but typically up to 6 months in a card-not-present situation should give you no problem at all. And once the complaints about this company start rolling in it will get even easier.
Mass chargebacks are a very powerful weapon in the hands of organized consumers.