Debit Order Not Returned

A debit order was deducted on my account after I had done an EFT for a callout. Prior to doing the transaction I checked with the accounts lady that they would definitely not deduct via debit order as well - 2 weeks later (after I'd sent the POP) they did! Now I've been assured twice already that the money would be transferred back on two separate dates and still nothing. Whilst trying to resolve this I keep getting cut off.