Credit card companies are very sneaky

I'm in the process of getting my credit cards paid off.  I'm not close to zero, but getting there little by little.  One of my bills was due on the first of December.  I paid off the account on the first of December.  It was such a good feeling to check back a couple days later and see that zero balance.  Well a few days later I looked again and I had a balance of a little over one hundred dollars.  I called to ask why and this is what they told me.

The statement was posted on Nov 3rd, but not due until Dec. 1st.  She told me that all that time from Nov 3rd until Dec. 1st my account was accruing interest on the balance.  The amount that is due Jan 1st is the interest from Nov 3rd-Dec 1st.  What??? I didn't realize that's how the interest is calculated. She said after I pay off the balance on Jan 1, the account will be at zero and stay at zero.

I know it's sometimes hard to make the payment before the due date, but if at all possible, make the payment as soon as the statement becomes available.  If you make the payment the first day, the amount you still owe will be less for the remainder of the month and therefore the interest will be less as well.

I don't know exactly how I got caught up with all this credit card debt, but I know that once I get the balances to zero, I'll never abuse them again.  I guess it's true about how you learn from your mistakes, I know I have.