I have an iPhone 4s which I have had for many years and love so much...unfortunately it is becoming outdated. So I bought an iPhone 6s from my friend who cleared the phone and gave it to me. He was a Bell customer and says the phone is unlocked. When i try to put my SIM card in, it tells me that the SIM is not supported??? Do I have to call Koodo? I have already paid for the phone to be unlocked. So I don't get it. Do I have to buy a new SIM card? and if I do can I keep my phone number?