OT phones

Since this is such a great group I thought I will ask a totally non-rr question here. I just received my phone bill from "Primus". I have no long distance carrier and just use their 10-10 number under what is called everdial. This bill had over $35 in 4 calls to the same number in Venezuela. I have never ever dialed outside the US. In my call to them they said they are checking and told me they never heard of this happening before. My question is can it happen and how? I need some ammo as to how the current phones work. Also believe me when I say _it's a given_ those calls _never came_ from this house.