You can try as much as you like, but you can't.
You can try visiting a branch and speaking to a consultant who will assure you it is now closed, but she will be lying.
You can try going back the following week and sign papers with somebody else who will assure you it will be closed, but nobody will care and nothing will be done.
You can try speaking to the call centre 6 months later who will tell you it is still open, but there's nothing they can do about it.
You can try to call the manager or anyone at that branch, but it will be impossible to get through.
You can curse as much as you like.
Your Standard Bank account will haunt you for the rest of eternity.
Not that you'll know it as you won't be receiving any statements.
You will not sleep again.
Previous posts and never-ending joy from Standard Bank:
Should I open an account with Standard Bank? No you should not.
More joy and why FNB is better