Here's the truth about RSVPs:

  1. Most of your guests will put the RSVP card in the mail on the RSVP date. Even if they knew months earlier that they would not be able to make it to the wedding.
  2. Some ridiculously high number of guests you would think would know better will not RSVP at all, assuming that RSVPs are only for people who are coming.
  3. When you call the people who haven't RSVP'd, at least one will say, "I won't know if I can come until the day before the wedding; I'll let you know then."
  4. At least one person will add an uninvited guest to the response card.

So what can you do to fight this? Anything you like. It's not going to help. Just remind yourself that when those lovely guests start planning their own weddings, they will find out just how awful it is to be treated the way they treated you. Either they will suffer a guilty conscience and repent fully for their sins, or they are beyond redemption and there's nothing you could do about it. Except, the next time they invite you to something, say you think you can make it, and then call at the last minute and tell them you decided to go to a movie instead.