I am Unicom card. The text message shows that the contract has not been returned, and there are more than 500 phone bills. Why is my balance still zero?

As you said, the phone bill not returned by Unicom mobile phone customers is a frozen balance, which is not in your actual available balance. There is no refund in the contract, which means that your mobile phone number participated in the prepaid phone bill contract. This frozen amount will be returned to you on a monthly basis according to the contract you handle, which can be used to offset your monthly rent;

If you need to inquire about the contracts you are involved in, you can log in to the Unicom mobile phone business hall client with the mobile phone number you need to inquire: select "Contract Rebate" under "Service"-"Inquiry" to inquire.

Tips: Because customers are located in different cities, there are differences in services that can be self-inquired in different cities. If you can't find it through Unicom's mobile phone business hall, you can call the local Unicom's manual customer service to assist in the inquiry.