well, just because they are going to charge you a high interest rate doesn't mean you need to close it. It's only a high interest rate if you are borrowing against it.
Here's my point. So, you have 1 or 2 cards that are charging you some abhorrent rate, yet, between the two, you have like a 5-10k limit. (just as an example). With no debt on the cards, that makes your available, unused credit higher, and bumps your score. Of course, if you don't use the cards, they will cancel on you. But they won't if you use the card, like, once every couple months, for something as inane as gas, and just pay it off within the grace period. This keeps the cards open, your available credit high, and you not paying any fees or interest that suck. Shitty cards can work for you, if you use them correctly.