I'm getting good at this!

Checking another statement online today (the fourth card I paid off), I found out I had been charged $10.06 interest - which I was expecting a charge because I didn't get my final payment applied before my due date. But ten bucks seemed like a large finance charge for like a $200 balance. So I just called to see what amount the interest was charged on. And I was told my previous statement's balance of $678. Which seemed weird to me. The rep told me that in order to keep from being charged a finance charge, you need to pay the amount in full - not over the course of the billing cycle. What a bunch of baloney! I wanted to scream that I'm just a poor girl trying to pay off her credit card bills and I can't just save $678 over the course of one month because I will spend it! But I didn't complain or anything, and the guy said in good faith they are going to credit the charge off of my account! I've saved over $13 this week! Sweet!