I've been going through the same thing and it drives me crazy. I finally switched my phone service to Embarq and was able to keep my number. There can't be a technical reason for not allowing the switch. Digital systems are designed to deal with those kind of details. Our number is XXX-348-XXX. It's the 348 part of the number that's causing all this grief. At the bottom of all this I'll bet there is undoubtedly an FCC or ICC regulation having nothing to do with technology and everything to do with protectionism.