Disappointment after the other!

I think I should just give up on FNB. They fix one thing and block the other. Its very frustrating. I have been trying to make an urgent transaction today and the message on my phone appear like".... We can't verify your device. For your protection we have blocked your transaction". Mind you I have been using the same device even yesterday so what has changed overnight I dont know. I have tried calling FNB, phones ringing non-stop. Next thing just being dropped on my ear. What should I do?