How is this bank still existing?

The service at Standard Bank is DISGUSTING! I sent an email on the 2nd September to amend my debit order date as I have a new job and get paid last working day of the month. There was almost an immediate reply asking for my ID number which I responded to. Someone then phoned me on the 21st September only to tell me this is not possible its too late in the month to debit and I advised that this was requested beginning of the month already! Then she spoke to her manager and I got told it will be done and I even got an email from Standard bank that it got resolved. So I the 1st it will be deducted, HAH! No the 27th it got deducted fine there was the money in my account, woke up this morning and GUEST WHAT! Another debit order went off. The staff there is very unhelpful, I asked for the manager to give me a call back and GUESS WHAT AGAIN, I am still waiting! This is disgusting and I don't know how this bank still exists with this terrible service!