I've had a verizon copper landline for 30 years. I have had optimum for cable and internet throughout that same time. I am currently trying to sign up for fios cable, internet and phone. I also have verizon wireless so i am trying to sign up through that account to get the home and mobile discount. However, when i select keep my landline number it says number unavailable. This is my number through verizon i am trying to keep why is it not allowing me? Thanks for your help.