No, at the moment there isn't an "ignore" button. I don't know if there is a script for that though.
To report a player that you think has a negative behaviour just take screens of the conversation and write a report under general reports. Without evidence staff can't help you, so remember screens.
Are there any form to block or mute someone? 'cause is there a guy who spend all his time to annoy and insult me...
I don't know how to report him :S
Since /ignore and /mute aren't a feature, just type /chl 0 to get rid of the chat. Also, take a screenshot of the issue and report it to the report section for results.