This just started in the last few days and does not do it in all accounts in my Quicken Classic Deluxe. This is so weird I do not even know how to word the question.
Normally credit card account balances are negative (red) in Quicken and a payment makes the balance less negative, i.e. adds to it. The balance is negative because you owe money to the credit card issuer.
Is the balance in this account positive (black)? Then when a payment adds to the balance, the number will get larger.
Extending the reply from @jim_harmon, IF your balance column is black, there's a couple of possible causes:
What needs to happen (if you're not truly in a "they owe you" situation) is to pull out your monthly statements an work back in time until you find a point where the statement ending balance and the Q account balance agree … then clear (change to either " " or "c") the CLR field and re-reconcile the account, month-by-month until your discover the error.
IF you try to reconcile more than a VERY few months (1, 2 or 3) at once, you might not find the error since there will be just too much data to view.
I agree with @NotACPA, compare your statements vs. Quicken, however, I'd check the first statement after the Opening Balance first, because if the Opening Balance is wrong, all of your other statements will also be wrong. I had that happen on an account and it took a while to finally determine the Opening Balance was wrong; if I'd started there, I would've solved the problem faster.
I misstated. In a credit card account, items in the Payment column made the balance go up and items in the charge column made the balance go down. After I reconciled the account against the statement, it made a huge balance adjustment but reconciling seems to have fixed the problem. It is working correctly now but had me freaking out. Thanks for the comments.