The balance refers to the amount of repayment that has been recorded in the account. If it is a negative number, it means there is an overpayment on the card. The available limit is 4208, 6000-4208=1792, and 1792 yuan has actually been occupied on the card.

There are two possibilities for the balance still showing an overpayment: 1. You consumed the money on the same day, and because the consumption on that day was not recorded in the account, the balance remains unchanged. After being recorded in the account the next day, the balance should be 1,792 about. 2. You have handled the installment business. The installment business is recorded monthly, and the unrecorded installment amount occupies the quota. Therefore, your account shows that it has been paid off, but the available balance has not yet returned to 6,000 yuan.