If I may, and with the background that I dealt with my wife's cousin about the same issue, this is NOT a Microsoft warning, of course.
You did the absolutely correct thing. For those computers with an on-off switch which is dual function for sleep, holding the off button for ten seconds completely shuts down the OS.
Rebooting does not "reboot" the browser and its links. Important to run your CCleaner targeting one or more browser histories. Only then should a browser again be used.
In dinosaur days, I used to unplug a desktop or remove the battery from a lap top. Same thing. Total power down. Brutal yet effective.
You most likely clicked to a link which was not the actual company you sought. The scams are hidden in and under seemingly legit icons on some web pages. I have seen them on gun sites, cooking sites and some oddball "prepper" sites as well as a usual list of Lefty sites.
A site with the "lock" logo in the address bar of the browser is safe. Others are not. Never ever click on a pop-up message. And never trust one, either. And never call one of these numbers.
Direct to Walmart and Amazon are fine, but get in the habit of looking in your browser's address bar for the "lock" which should appear to the direct left of the URL.
Best wishes.
Thank you. All good to know.