AvastSVC.exe auto sutdowns PC everday AVAST Support HORRIBLE @ resolving

[REDACTED]

I have been an avast premier user for over 5 years.  I know have a problem directly related to AVAST software as noted by the event logs.  I can find out to correct this issue.   Everyday while doing work or in a pc based phone call avastsvc will shutdown the pc without any warning or asking to shutdown.
Call Avast Support and all they do is try to tell me i need to pay for advanced support services.  Now i am going to uninstall AVAST and put EST AV on my system.  Thanks Avast for causing me so much grief everyday with this auto shutdown annoyance.  HORRIBLE SUPPORT for issues created by avast software.
WIN 10pro 64bit OS
The process C:\Program Files\AVAST Software\Avast\AvastSvc.exe (MLM-LENOVO-Y15) has initiated the shutdown of computer MLM-LENOVO-Y15 on behalf of user NT AUTHORITY\SYSTEM for the following reason: Legacy API shutdown
 Reason Code: 0x80070000
 Shutdown Type: shutdown

[Pondus]

Call Avast Support and all they do is try to tell me i need to pay for advanced support services

Phone support is outsourced to a third party company

best support is here in the forum, and it is free   

you can contact avast support here (also free) > https://support.avast.com/support/tickets/new

[Eddy]

What exact avast version ?
Any other security (related) software installed ? (or was there)
Did you schedule a scan ?

[RejZoR]

Only logical thing on avast!'s side that would trigger this are Scheduled Scans that have a "Shutdown after scan" flag enabled. Otherwise I can't think of a single reason or scenario why avast! would do such a thing. Have you imported any 3rd party avast! config settings or created your own scheduled scans? This is the first thing that crossed my mind as soon as I've read about your problem.