I completely paid off one of my credit cards last month. I just checked my statement online, and now no more zero balance, they slapped on interest. Is that right? I had always thought if you pay off a card in the middle of a cycle, that's it, since when they calculate the interest at the end of the cycle, they use the current balance, which is zero, and obviously, any percentage of zero is zero. Or am I completely wrong on this? Thanks