-Online balance: follow the link to merchant's official balance check website.
 You will need to fill in card number and pin so as to retrieve card balance.
-Phone call: call the merchant's support number and ask if you can check card balance. You might be able to get balance on the phone after providing card details.
Invoice/ Receipt: the remaining balance of the card is printed on the shopping invoice / receipt.
Store Counter: usually the card balance could be looked up at shop or store counter