I've been a YNABer for almost a year now, and feel like I've figured most things out. However, I was today year's old when I realized that credit card refunds do not go back to To Be Budgeted or to the Category from whence they came; they just sit in the credit card line item, waiting to be plucked like so many ripe cherries! It feels like found money!
So your CC Payment Available was larger than your debt (i.e., the account balance)? Yep, put that excess somewhere useful!
FWIW, I assume you mean "rewards", not "refunds". Refunds and returns should be categorized to the spending category of the original outflow, and this will also adjust the Payment category. Rewards are typically categorized as To Be Budgeted, but confusingly they don't actually show up in TBB..