Cash deposit (internal balance) is an estimated value that stands for a sum of real money of a user, which he has in his profile and can use it for orders purchasing.
Unlike a virtual balance of bonus money a deposit is a sum of real money.
To let users top up their deposit you need to create a product with 'Money to deposit':

Create an offer with a price of 1 rouble for this product and mark in a form that a user is able to specify a needed sum of money on his own:

When a user fills in a form and purchases this order, paid sum of money will come to his/her deposit.
You can see a deposit balance on a user card:

Administrator is able to top up a user’s deposit as well.
To let him do it you need to press 'User' - 'Balance' - 'Create a transaction', specify a user, 'Deposit' type and a sum of the transaction:

You can charge money off from the user’s deposit.
To do it specify a negative sum:

User always can take money from the deposit when purchasing an order:

Also, when cancelling some paid order a payment could be charged to the deposit.
To do it make order’s status as “Cancelled”, make payment status as “Returned” and save changes:

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