Poor service from FNB due to their own errors, no quick customer service to resolve

I called the call centre 2 weeks ago to raise the credit limit of my credit car. To my knowledge, I am a premier client. Limit was increased. Years ago I had sent a letter to FNB requesting that no changes to my accounts to increase limits etc was to happen to my accounts unless I expressedly asked for it. I DID NOT ask for the type of account to be changed from Premier to Private client. Now, having to be inconvenienced and nothing has been done about it yet, due to someone at FNB's error by them changing my banking type without my permission...I yet again, cannot access my funds due to negligence or improper procedures being followed at FNB.