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.
