Please don't waste your time refreshing a site a thousand times. PLEASE! Go onto the CS registration website, read down a little and find the "Email Reminder" link. I was in your same position, my test date was Jan 9th and I was supposed to be done by December. I set reminders for the nearest site, they come in one month increments, and now I have a test date in about a week. People drop their dates ALL THE TIME!!! My mailbox got flooded everyday with "available dates" to the point where it got annoying. There was no fee to change, and I just jumped on something convenient. But that's the key, you gotta jump AS SOON AS you get the email!
Good luck. You'll find something, no problem!