Not willing to pay back from Suspense Account

I have paid money to a Standard Bank account number, which unknowingly was incorrect and does not exist. I tried to reverse the payment through my bank (FNB), but it failed because the payment was already cleared and now lies in a Standard Bank suspense account. I phoned Standard Bank and they simply refered me back to FNB, saying they don't know in which branch's suspense account it is - not asking me ANY questions to try to get the information they might need to assist!