Pennies or Plastic?

AT&T wants their money. Today I received a bill from them for a whopping $0.04. Yes, you read that correctly- 4 cents. Apparently, they over-credited me way back in February and they want what is rightfully theirs. They are willing to spend $0.42 in postage plus ink and paper in order to get their $0.04 from me.

I'm debating between sending them four pennies in the mail or using my credit card (and making them eat the credit card fees all companies pay). Help me decide by voting in the poll below