I paid the phone bill and received the recharge SMS. Why is the account balance zero?

According to the information you provided, it is not excluded that the balance is still zero because your prepaid phone bill is not enough to deduct your arrears. If you owe money, your available balance is negative or zero. You can check the amount you owe through the following channels:

1 Log in to the online business hall /02DAa home page and click "phone bill inquiry" > "account balance";

2. After logging in to the mobile phone business hall client, click Service > Query > Telephone Fee Query > Account Balance;

After entering the page, query date, customer name, available balance, mobile phone number, available balance and frozen balance information will be displayed.

If this is not the case, it is recommended to contact the Unicom customer service to which the number belongs.