When the bank won't communicate with their clients

I have been an FNB customer since my small business started in 2015. In 2017 somewhere mid December I realised my business account was frozen as i was trying to buy data, this was after i had money paid by my client in the account. I immediately went to the branch which was confirmed that indeed my business bank account was closed. I then requested the consultant 1 to find out why was it frozen, she said she will send an email to Samantha Triegaard to get the details . A week later i went to hear why, she then told me that she (Samantha) have not responded and she was not answering her calls. I went to another branch I then asked to see the business manager, I stated my story she then tried come me down and told me it could be the bank is saving me from some unwanted activities in my account, I accepted it and she also promised to send Samantha an email I called a week again later to check if she has some news for me again she had not received any response from Samantha. January I came back from holidays and went to the bank again requested consultant 2 to find out again why my account was closed, she send an email again to Samantha and promised to call me when she get the respond, fortunately she responded and consultant 2 forwarded me an email from Samantha. She said i had received payment that was not meant for me and she attached a conversation between people i had no idea who they were amongst other things. I immediately tried to call Samantha as there were contact details on her email signature, but the number was forever engaged , i sent her email she never responded to this day, in short I went to FNB website to complain about the lack of correspondence,A certain Mondi responded said she will get back to me soon, He also never got back to me i sent email i tried to call nobody was talking to me . i complained again i got the response from general email ,also never had feedback. I went to bank city hoping to get some answers from Samantha, when the reception called her phone was engaged as always, they then called her manager basically thats how they got through her. she came down after 2 hours of waiting for her with a piece of paper on it she wrote amount of monies and a case number basically i went all the way to JHB for her to tell me to send her paper work she did not even know that i had sent all paper work including a police affidavit i told her the branch sent her everything already but I came back sent her everything again later tried to find out if she had received she never responded. I have been trying to this day to email Samantha she just does not respond to anything and that is very frustrating is 2019 I still don't know how the investigations are going, i still can't access my money, i have be patient i Just want to know the progress of it all and this has affected my business negatively.