I made a payment about 9 months ago to pay off the balance of my credit card. For some reason the payment never went through. I didn't notice. The credit card company also didn't notice that the funds never came through and gave me credit for paying off my balance even though the funds never actually left my bank account. After closing the card, they audited my account and discovered that I owed them the money and are asking for it. Am I legally obligated to pay?