Cant run my business like this.

I have a business account with Standard Bank for years. A new Business Manager Elize started to work in the Tzaneen branch and my problems stared. I have an overdraft and all of a sudden it was blocked, no Reason. The branch did not know why and could not help. eventually customer service unblocked it. Then I was asked for certain documents for a review. I asked the bank for statements as my accountant needed 10 working days. I received them on the 16th April and Three days later my account was blocked. I inquired and was told the statements were sent on the 9th but no proof was given. Eventually my account was opened. Yesterday at 12:51pm I received a request from the bank to complete documents. These were completed and sent at 1:38pm. This morning I found my account again blocked and I cannot get hold of anyone at the bank. On Friday 8 May we were at the Bank with Elize who assured us all was in order. I have sent an e-mail to customer care but they don't bother to reply. I had a review done with financials just over a week ago and now they want another and blocked my account. I am running a business with lots of money going through my account.every day.