My mother bought a white Iphone 4 a couple of months ago and has started getting intrusive calls on it. The number is unlisted, I've had her register on Canada's "Do not call list" for telemarketers but it takes a month for that to go into effect and it won't stop all of them. Is there a call blocker application that's relatively simple to setup and use? She lives far away from me and is not tech savy so jailbreaking is not an option. Any information would be most appreciated.