Unfair listing

I don't understand how things work in your business but in June their was an issue with my account and when you tried take money from my account it failed you then told me not worry it would be taken on the 10 July which then did go off. Recently I app**** for vehicle finance and it was initially approved but today surprise surprise I find out it has been declined because you listed me as non payment/missing payment I have never seen such if I really missed the payment you should have not told me to wait for the 10th I could have paid ASAP. I honestly don't understand is that how you treat your customers? I called you to get clarity and explained what happened and was told that shouldn't have happen and they would send me a letter to send to my credit provider for me the letter doesn't exonerate me, it really frustrates me because it states that I have call the credit bureau for more information. Can someone please sort out it out