All cards are refundable. No concept of "Non-refundable" cards. Check time: 3 minutes. However, to play a fair game - If your balance is between 1-50 USD, you can check 50 cards/day. If your balance is more than 100 USD, you can check 100+ cards/day. Even if you exceed the limit, ask refund using ticket system.
All your feedback and opinion is appreciated, I will work towards it to make your experience a better one! Always open a ticket to resolve any issue, trust me I am a friendly guy.