Debit Order Switching-Bad Service

My Dad recently moved his accounts to FNB. We had requested for the debit orders to be switched when we opened the account and we received confirmation via SMS & FNB Call Centre that the debit orders were switched. One of these debit orders was for Old Mutual and last night , we received an sms that this debit order was processed via my dad's previous bank account and now this debit was unpaid . This is very unprofessional of FNB to treat its clients this way. I would like FNB to correct this by contacting Old Mutual and arranging for this debit order to be reprocessed through the FNB account and to also reimburse my dad previous bank account with the relevant unpaid fees.