Poor Service on Private Client Account

I am an FNB private client and I am appalled by the slow response/lack of response I get from my assigned 'private' banker and the private clients suite. I sent a query on Monday morning to both my banker and the suite, the latter responding with a reference (CAS- ********** -K8X6R5) and supposed 24hr turnaround time. I still haven't got a response from either. Historically my assigned banker has been difficult to get hold of, slow to respond, and his standard answer is to direct me to phone a hotline either because he can't help me himself or claims phoning will be faster. There really is no value in the in Private Clients other than slightly better eBucks benefits. I want to downgrade my account.