installment deducted for paid up loan...still no refund!!!

I had 4 personal loans with Nedbank once upon a time!! i am slowly paying these off and in Feb 2018 I off my 3rd loan. But I was still debited the installment month end.

i was told this would be refunded to me as there was nothing i could do about the debit order!

A month later im still trying to get help. When i called i get sent from Pillar to post. No one can help me. No one can track the payment! i dont understand how something like this can happen???

Their consultants are useless. No one..and i a mean no one can ever help me!