Standard Bank not taking responsibility for their own mistakes

I had a student loan with Standard Bank, this account has been paid off and closed, however, Standard Bank still took my monthly debit order. I have phoned numerous times and have been to the branch to query this. The answers I have received vary from "Wait and see if it bounces back", "It might take 24-48 hours", "It will take 72 hours to bounce back", and " It is not Standard bank who took your money, it is your own bank and you just don't understand how these things work". The point is Standard Bank has not been able to nor were they very interested in helping me.

To them, I am just a number and my income to small to really spike their interest.