Worst bank ever

I complained about standard Bank a few days ago and I've been trying to call then back on the number they use to call me but each time there is no response I've tried to reach them via email to set an appointment as to when they can call me but that too has drawn a blank, in the meantime my problem persists, I just want to close all my accounts with them because wow, you invest your money and then it doesn't generate any interest and it disappeares in their system because they messed up hate this bank