Capitec Bank blocking money that have no relevance to a "suspicious transaction"

I received a amount of money in my Capitec account on Sat 5 July, and immediately move it to another bank. ±4 Hours later Capitec called me from their ***** department. (While I was on call on another phone) I told the agent there is not concerns, I received and transfered the money. I said I am on another call and need to drop. Then they said unless I speak to them they l can not release the money. Which was point less, as the money already left the account. No need to "release" money on their side. I told them I REALLY can not speak to them at the moment as I am busy on another call and asked them to call me back. The agent said they can not call me back, after which I terminated the call, AS I AM BUSY on another call. 15 min later all the money in my Capitec accounts became unavailable, even though in has NOTHING to do with the transaction they called me about.

How can they not call me back later? It is call "customer service". If I have to go to the branch to sort it out, closing my account would be part of the "sorting out"