I've had both Rogers and Teksavvy tell me that they couldn't change a phone number.
Our current landline has a number we don't like, and a former owner who didn't pay some bills, so we get automated calls from a collection agency several times a week.
My wife had trouble remembering my new cell number, so when we went back to get hers, we asked if I could change mine.
Things have changed from the days when we had the best phone company and worst cable company in the world, both with monopolies.