Bad customer service

So my spouse and I decided to apply for a bond with Ooba home loans,long story short we were rejected due to a few circumstances. One of those circumstances was due to the Smart Spend Loan,which FNB has listed me for missing payments. Now one would say yes if you miss payments you can't complain about them listing that true,but when it is a mistake from there side then how can they do that.

So what happened was that they did not debit my account like they were supposed to an after numerous calls and then I to revert to Hello Peter to finally get hold of them to sort it out. They go and list it as my fault.

So I call FNB and I explain to the consultant ( Bonisile Simelane) and ask her that I would like FNB to give me a letter explaining that it was a mistake on there behalf,because that letter I then in return send it to Experian so that my credit ratings can be rectified. She in returns tells me that FNB doesn't give out letters for that,so I asked her to let me speak to her manager. Shen let me hold for a few minutes and gets back to me and tells me the following " That her supervisor says that I must send them proof that it shows on my credit report and only then they would send me a letter. So I did what they asked,I didn't get any feedback since then. Not a email saying documents received or telephone call or even a sms. So I tried calling but no luck.

So I ask you FNB, is your mistake going to be blamed on me now.