Rather than trying to justify your purchases after the fact, just stop using the cards once you see that you won't be able to repay the debt. (nasonlawfirm.com)
Once your credit score has risen to the point that you can apply for a better card, don't close or stop using your card for fair credit. (creditcards.com)
Then also stop using the card and you'll see your balance disappearing. (mymoneycoach.ca)