No, Mozilla doesn't use telephone numbers for any type of support. Whoever that is is trying to scam you; ignore that message. https://thisphone.us/8556716022

Plus, I deleted that attached screenshot of a Death Certificate - you shouldn't post private information like that on the internet. True that type of image is safer to post in a public forum, than posting text data that can be "scrapped" in usable format by "spyders" crawling the web. But a ne'er-do-well could still read that image and could possibly use that information to steal that identity.

thank you so much for your help !!!!!

spiritblue said

received a shutdown warning,was told to call 855-671-6022 for support, is this actually Mozilla?

Also https://support.mozilla.org/en-US/kb/avoid-and-report-mozilla-tech-support-scams

i shut down my computer with no problems.