MAC Book locked up

My wife’s computer is locked up. While cleaning out old emails her computer stopped working. On her iPad she received the following message…

”Important security message. Your computer has been locked up. Your IP address was used without your knowledge or consent to visit website that contain identity theft or virus. To unlock the computer, please call computer support immediately. Please do not attempt to shutdown or restart your computer. Doing that could lead to data loss and identity theft.”

The number given is +1-8***. When I attempted to call the number all I got was a busy sound.

the threat detected was : Trojan Spyware. App: Ads.fiancetrak(2).dll

Any and all help is greatly appreciated.

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