It sounds like you have a stalker. Lock your door, bar your windows and peep out menacingly at kids every now and then, Because you never know who it could be.
Someone from school or wherever prank calling you.
My friends do it to me all the time. They adopt a strange accent then tell me about the state of biscuit marketing in Ecuador. I pretend to be interested to waste their credit.
There is or never will be a caller from any type of Powder Toy groups or main site. Powder Toy is created by a group of developers who contribute to source coding. Not a company.