Did I fall for a scam by calling that number
Unfortunately yes.
An adserver (or two ...or three...) is serving the scam pages when you visit entirely legitimate web pages - I know for a fact that CNN, YAHOO, and Weatherunderground (wunderground) use third-party adservers that serve these scam pages; I'm sure that many more sites also are using the same adservers that serve up these bogus "ads" that turn into scam pages that take over your computer - note that they take over your computer not by actually taking over your computer, but instead by opening pages so fast you cannot do anything INCLUDING shut down your browser - alt-tab usually works, however, so you can kill it that way.
The adservers are NOT the guilty ones, BTW - they are simply serving ads (for example, it's quite possible that one of Google's adservers served at least one of the scam pages). I found that the only way to stop the scam pages from showing up was to install an adblocker - that stops ALL ads, of course, so may not be what you want - and some sites, such as Forbes, stop serving their own pages if you block their ads. Yesterday I temporarily disabled my adblocker because I wanted to view a Forbes page redirected from Yahoo and, before I could click on the Yahoo page's link to Forbes, a Yahoo adserver had already served up one of these scam pages.
Before I blocked all ads I noted down a group of sites served from just sitting on a Yahoo page that I believe were the source of the scam pages (at least indirectly if not directly). This is NOT a complete set, of course:
softwarecentraldownload dot com/campaign/problem6
nextoptim dot com/script/packcpm.php
tracking.beginads dot com/
maturetubex dot com/category/All/ctr/9/
xctraffic dot com/in/__x_skim_ts/
www.heresurvey dot com/
engine.spotscenered dot info/Redirect.eng
There are related bogus pages served up on mundane sites that open a new tab, switch to it, and present a "survey" from what appears to be your ISP; your ISP, however, has nothing to do with these "surveys".