Poor service from business banker

So I have banked with Standard Bank for over 10 years hence it took me a while to express my disappointment with the current situation. I was assigned a business banker who has shown on many occasions that she doesn't have time for me. Calls go unanswered and emails ignored. Even call center agents have failed to get a response from her. So I finally requested to be assigned a new banker...guess what, even that required her to execute or her superiors. I asked for hee superior's email which I was given several weeks ago. I sent an email but up to now not even an acknowledgement of receipt. So this is my last option. Hopefully someone at Standard Bank will be able to assist. I don't like to make empty threats that I will change my bank and all...but of course that's exactly what I will have to do pretty soon