bad service from a banker, no follow ups on my request, complaints being ignored for over 3 months now

its been 3 months asking the bank to give me an alternative banker as the one allocated to me does not have the best interest for me, every request I ask from the banker by the name of SONGO she tells me its impossible, no attempt to go fight my case with credit she just decline me like that, I logged a call with the complaints department 3 times no one has even attempted to try and call me, the last time i had a good banker with investec private bank is 2 years back, the rest of the time till now i just hate investec private bank and I really hate the client service i deserve, or is it because I am black ? do I have to send my blood group to be accepted as their clients? I am very irate with this bank especially the banker allocated to me .