iphone locked when i switched network proveder from Tesco mobile to Plusnet mobile
I have just switched provider from Tesco mobile to Plusnet mobile. When I put my new SIM card in I get the message that SIM Not Supported. Phoned Plusnet who say iPhone has been locked so contact Tesco mobile to get it unlocked. Tesco SIM now obsolete as fave left that network. They can only send me a code to unlock but that is no good as my iPhone won’t move on from the SIM not supported message, I.e. I cannot access the keyboard, or anything else. Please can someone advise me what to do as I cannot use my phone even though I am now a subscriber to Plusnet ( who tell me they have no way of unlocking my phone)
iPhone 5c, iOS 10