First of all, the quota of 9 is fixed, which you understand;

Unpaid bills refer to the amount of arrears or consumption that has not yet been counted in the month;

based on my experience in using the Bank of Communications card, the unbilled bills of Bank of Communications are generally delayed. It may be that you have spent less than 9 yuan several times this month, and then repaid it once, and then spent it again, resulting in the amount of 13, yuan. Moreover, unbilled bills are not counted, and based on the actual bills issued next month, how much do you need to change after billing statistics, then you have more.