I've always heard movistar takes over night to activate and have been told its next business day so that would trash the weekend. I don't know if this is true as I've always used CTI. That said as I mentioned above when trying to direct dial the US from CTI I would get an error message of some sorts. Which of course because I'm not fluent in spanish i can not follow all of.
Those who have used CTI, is there an IDD code you can use?