Manage Balance Manually

Hi, i need to Manage the Balance of my Users Manually, because i have a Physical Store, where they can buy things using their Wallet Money.

Is there any chance of when someone come to the store, and buy anything, i can edit their wallet balance manually to the actual one after paying the products he buy?

Of course, i want a mail notification where it said that your new balance is X.

Is this possible?

Thank you.