ABSA Security Shambles

Got a call from a 012 number, wanting personal information. Guy said his name was Robin and he was from the ***** department, but I told him I don’t know the number and am not comfortable sharing personal information. Next thing I know my banking services are suspended. I phoned ABSA about this but they’re not willing to help. Instead, they say to not give personal information out to strange numbers whilst at the same time telling me that their ***** department contacts you from strange numbers because their ***** line can’t phone out. I wasn’t given an option to confirm any information or told during the call of any alternatives. Seems ABSA as a bank is definitely not taking the security of their customers seriously at ALL, and they want me to give out personal information to unknown numbers. I lodged a complaint but after ABSA couldn’t resolve it satisfactorily, they just sent emails to inform me that the complaint is closed, even though I still don’t know who to give what personal information to next time this happens