This type of call can originate from many of the Carribean islands. Each apparently has it's own exchange (not area code) for toll calling numbers, like US 900 numbers. They can charge several dollars per minute over and above any long distance charge. All they do is try to keep you on the phone to rack up minutes and bux. They all use the North America country code of "1" and an Area Code for their country. If you are not sure, look up the area code online and don't call back if outside the US or Canada.
Cener, Ingo, Rilibald, Hesred, Halras, Loringo
Arkenstone (ex-Elendilmir) - The Osgiliath Guard