Poor service

I have never in my life received such poor service , i having communicating with FNB via chat and call just to change my debit order banking details but it seems like no one is willing to assist, i am being referred from pillar to post , i went to boulders they also unable to assist .is that how you treat your client . I am very ****ed as i have accepted the debit order mandate but when i ask via every platform either chat or call and branch consultant no one has an answer of why my debit order doesnt go through instead i am advised to make cash payment. This is nonsense i must say