I am staying in Niagra, Ontario, Canada. I have ATT and I know that there are rates for international texting. I know it is 50 cents per sent and 15 for received. But does that still count even if I am sending a text to a U.S. number inside of the U.S. Also, is it possible that U.S. coverage still works for my location? I am less than a mile outside the US border. And what about if both of the phones are ATT