I would be cautious to call and inquire about not being charged. Your honesty can lead to a headache for you. It would be terrible if you called and they charge you for it now, then in six months or so the original purchase hits your account.
It is unlikely, but not out of the realm of possibility that this could occur. Just wait it out. If they hit you with the charge six months later, you'll understand why.
Just my 2 cents....
Mike M