Banker confusion

I needed to contact my banker, and went to find the details on my banking app. I know my banker to be "Banker A". My app now says my banker is "Banker B". This was very confusing to me, as I has received no communication about a change of banker.

I tried to call both bankers on numerous occasions, as I needed assistance. Neither of them were answering my calls. I tried on different days and different times to contact this both. My calls have never been returned. I am yet to be able to reach either of them.

This is highly unacceptable. I now don’t know who is actually my banker, and no body is responding to me Why am I paying for a service I can’t even use?