Disgusting service related to a small issue

I am highly dissatisfied regarding Standard bank service I have been on hold for over 20 minutes utilizing my own airtime and being moved from pillar to post regarding a small issue. I requested a lady to call me back and she advised me point blank that she cannot call me with no reason as to why. I understand their call volumes are high however where is TCF app**** here? I fail to understand as to why can one struggle so much with them. I wanted to switch and move to Standard bank from my other banks but most definitely I will not do that cause i will always be experiencing such treatment which i will not stand.