Grime fighter shutting down my computer?

I have been trying to find a way to contact Avast from New Zealand many of these companies have an email help system but I can’t seem to find one. For some reason since I have downloaded one of the newest versions of Avast Free it keeps shutting down my computer effectively crashing it, and a full page colour picture of the grime fighter (thing) comes up saying that Grime fighter has put my computer to sleep and avast is contacting its technical support, the only way to get things back is to turn the computer off but none of this seems particularly good and I was wondering if anyone can help or suggest how to contact Avast other than very expansive toll call.Thanks Debra.

avast grimefighter forum section is found here Avast Additional products https://forum.avast.com/index.php?board=44.0

contact avast support https://support.avast.com