They too called me to say that my account was not paid, but the lady gave me a full credit card number I have never had, she also had my full name, address and confidential things. Bit scarry when you know they don't have access to the full card number usually. They maybe have a leak internally.
I will make an official complain with my credit card company...
If it is Yak.ca, then I believe that is the long distance carrier. You dial 10-15-945 and then the phone number. I use it and it is on my Bell phone bill listed as Yak. I received the same phone call. Long Distance, I picked it up and no one.