SHOCKING, SLOW SERVICE ON A BUSINESS ACCOUNT

I have bought a business, where the existing business account is with FNB. Trying to change the information has been nothing less than dreadful. It has taken weeks of being pushed from pillar to post. I have submitted EVERY document requested.The overdraft facility and linked cards were removed with a dash of speed, but I cannot get the personal information changed from the previous owner to mine, so that I can function as easily as they profess in all their adverts. I have emailed, visited a branch and been on calls with a Business Banker and their call centre. I am no further and don't even want to give them one star on this rating. Clearly, their customers aren't as important to them as they make out they are. I'm disgusted and frustrated and all I want to do is run my small business!!!!!!!!!!!!!!!!