A lot of good info here. Since tge original question is about tax returns and credit cards, I will point out that if you usually have CC bills and usually get back $5000 for a return, then you should really change your withholding amount to actually have the cash to pay for things you otherwise use the CC to purchase. This way, you don't pay interest on your CC throughout the year while you are lending your money to the government interest free. Your scenario is a perfect example of this.
In essence, all the CC interest you paid this year could have been avoided if you did the above. It's your money, take it as soon as possible. Don't lend it out the whole year to the government while paying CC interest. Change your withholdings. Good luck.