Install any translator you can or open up a page & copy/paste... now is the time to try anything to stop this...
Sorry this is happening
Hmm... could they not trun off your site i.e. do a full backup and of the DB then place one of their messages saying "this site temporarily Hosted by so&so" or the usual "they have not paid their bill message" for a few hours to see if the person is trolling the site then they see it down, it might trick them for a day or so... I dunno but this make me mad & sorry again

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Mike