the so-called minimum consumption means that if the minimum consumption is less than 31, you will be charged 31 according to the minimum consumption.
if you exceed the minimum consumption, you will be charged according to your real-time fee.
The voice call fee outside the package is your extra call fee. You can call the customer service directly and they will tell you the reason in detail. You can also check online yourself, but you may not be clear about it, and you will have to call customer service in the end.
I suggest you ask customer service and change the package that suits you.
that's it. thank you for your adoption.