How to add SMS senders to trusted list after blocking all unknown numbers

[Onursari]

Can someone help me? I want to block some spam senders like BET365, DATBANK but when I click to block it says I have to turn on blocking unknown numbers then it blocks all unknown numbers. When I get a phone verification from a bank, I try to add it to trusted list but it doesn't do anything. I click Trust button but it doesn't give an answer. How to solve this problem? These SMS are really annoying.