I had this problem a few years ago while this kind of thing was still new. I am on dialup and they did charge me for this same thing, calls to Africa. I tried to argue this issue with them, but their answer to me was that it was dialed from my phone. This got me really mad so I told them that I no longer wanted long distance phone calls allowed from my phone.
They can give you an option of not having international long distance calling, but they will charge you a few dollars for this service. You can also stop all long distance calls too for another small price. First I would call them and dispute this charge and see what thay say.
I had decided to start using a cell phone because I have a child working the night shift and drives now too. So I purchased a family plan cell phone for all my long distance calls now. I figured if I was going to be charged for these type of calls that I might as well use this money for a cell phone and not let someone else get the gratification of free calls. I feel like I have beat the phone company and the internet hackers by doing this and it is doing my family a service.
My phone company looses too in the long run because they can't make any real money from me on long distance calls. This is their stupidity. I don't like getting burned!!!
I'm not ignorant, I just need more learning!