Was not charged for an online purchase?

So, I bought a pair of shoes online. Like usual, a pending authorization appeared online in my bank account statement. Then today, I found out that I was reimbursed for that item, even though the item is here sitting next to my fine self ;) How much time do I have before the company can re-charge me? I believe there is a certain amount of days and after that, I wont be obligated to pay, but I'm not sure. HELP