Why can't China Unicom 3G Card 96 yuan Package B use 500-minute voice call?

In the tariff standard of 96 yuan Plan B of Unicom 3G package, the domestic call duration is 450 minutes, and the domestic traffic is 80M. Your other 500-minute call duration and 500-meter traffic may be the call duration and traffic given by local users. If you use it beyond the scope, you can only use the domestic call duration and traffic in the package. I suggest you contact the local Unicom customer service to check.