With Quick Payment, your saved credit/debit card (“bank card”) will be used to automatically reload your eWallet and pay with the exact amount needed to complete a purchase if your eWallet does not have enough balance for it.
For instance, if you buy an ice-cream that costs RM8, but you only have RM6 in your eWallet, your saved bank card will be used to automatically reload your eWallet with RM8 so you can pay for your purchase seamlessly. You will still have the RM6 initial balance in your eWallet.
Below are the articles that may be useful for you :
What can I use Quick Payment for?
Why should I use Quick Payment?
How do I set up Quick Payment?
How can I change the bank card used for Quick Payment?