Failed debit order changes

Pathetic service, incorrect date captured when I took the loan and first instalment bounced. Called call centre and I was told they can’t help because the debit order has gone off I must call back. Called on Saturday and was told that department is closed, called on Monday after 8am and a lady name Glanys cut my call - this is very unacceptable. I can’t be begging you to take my money and this will have a bad effect on my credit record!