Homeschooling DISCRIMINATION????

I was calling around some summer camp places to enroll my child in.
I called one place a week ago, and asked about their camps info. The lady was telling me what kind of activities they do during the camp, prices, etc...

Then I told her that my child is homeschooled but that he completed his grade.
She suddenly said..OH, really..
And then she said that they are all filled up.

At first, I didn't know what to think, but I felt that they just didn't want to deal with homeschooled kids, so maybe they lied.

Today I called again (I tried to sound a little different so they wouldn't recognize my voice)....
I wasn't sure if it was the same person talking to me, but she asked me if my child completed K grade. I said yes, and she went on telling me that they have some openings left. She told me all about the program, what they do, etc. At the end of the conversation, I asked her if they required anything from kids beside payment for school, because we were homeschooled (like shots forms, etc)...
Her voice suddenly went sour, and she said...'OH, he is homeschooled...and she went on trying to tell me mumbojumbo about completeing grade...She said she had to ask someone about the policy on homeschooling, because she didn't know if it was ok...

I could hear contempt in her voice (like there is something wrong with people who teach at home...).
I asked her when I call back to find out about the policy. She sharply answered that she'll be there tomorrow at 9:30. Suddenly, she didn't sound very cheerful like in the beginning.. It was as though she was pissed off that she had to deal with me now, and couldn't lie about being 'filled up'. That's the impression I got.
I am going to call back tomorrow and see what they say. It would be interesting if they suddenly got all spots filled up. I wonder if it's discrimination and illegal..
Any ideas?