You can check your balance by entering the application, from the main menu you can see at the top that your balance is in white, to refresh the balance you just have to click on the arrows next to your available balance.

To check your card balance, you can also use the IVR, by calling 2266-8126, option 4 for CashPak and then option 1 for Balance Inquiry. They will ask for your card details and date of birth.