Hi, this is happening to me too. Just transferred from EE. It's driving me nuts. I called 150 and was told to test the SIM. I saw another thread on here that says that for someone else it was a problem with the routing from Orange to Virgin. I'm heading down to the shop. Have only had the phone a week and it was fine until yesterday!
Got a new sim delivered. Fixed the phone and everything was fine.
Tried signing up to new bank account app on TSB again. When it came to getting phoned with a passcode, phone bricked again. Exact thing that we believe caused it first time round. Back to having a not working phone. Going instore tomorrow to get another sim.