Girl you need to raise hell and get your extra cash back!!! If you specifically paid them the extra $$$ to have a private affair closed to the public, but they are going to allow 4 others in the area, then they are violating the terms of your contract plain and simple. It doesn't matter how few public guests are allowed, that's a load of shit!!!
Raise hell, and get that money back. Wow, I'm totally pissed for you ~ I hate when businesses think they can just bend terms in their favor thinking it's ok. Uggghhhh