Meta has a weird messaging system here in Forum.

[LeMagz]

Case unresolved, cannot message for my unauthorized purchase refund.

YOU CAN ACTUALLY MESSAGE SUPPORT HERE: https://www.meta.com/help/support

[TheAntiSocializer · Accepted solution]

Hey @LeMagz. I'm sorry to hear you were having some issues reaching back to support here on the forums, but I'm also glad to hear you were able to get in touch with someone through the official support site. 

From my experience on the forums, it looks like that's just something added as a bit of a potential security/spam filter. If you run into this in the future, I do suggest waiting a little while before attempting to send a message once more.

For anyone else running into this, if you're still not able to send a message after waiting a little while, I recommend also reaching out through the link provided by the OP.

I'll take this feedback and pass it up internally to some people who might be able to get something in the works for this.