ABSA TAKING MORE THAN IT SHOULD

I have been receiving huge amounts of money into my Absa cheque account from my clients and allowing them to take as they please. Now the most recent one was on the 24th of March, a client deposited money into my account, they usually have this security check whereby whether money goes in or out it has to go through a process of 4 hours. I check my balance, the money was sent but Absa took all of it. I thought it was because of the security check but 2 days has passed now and my balance remains on a decifit. I hardly have time to do walk-ins at the bank. Please help