Product: Credit reporting, credit repair services, or other personal consumer reports

I have a problem with XXXX XXXX my mortgage company. They put a 30 day late notice on my credit report because my taxes went up and I did not know about it so my payment came out of my bank automatically as it does every month for the same amount not the new amount. If I had known about this I would have fixed it right away. The only way I found out about it was through a notice from the credit bureaus which I monitor daily because I am trying to secure a loan to build a new home and need my credit score as high as possible. As soon as I got the noticed I called XXXX and paid the {$80.00} difference. I asked them to remove the late and they said no because its accurate and they tried to contact me. I have NOT spoken to anyone from XXXX XXXX about this issue prior. They said they sent letters and made phone calls. The only things I received from them is calls to refinance my mortgage which I have told them numbers time I do NOT want to do. 
First I spoke to : XXXX XXXX XXXX XXXX XXXX She said the information was accurate and she would not be able to do anything about it. After requesting to speak to her superior for XXXX minutes she finally transferred me to someone else. That someone else was : XXXX XXXX XXXX Leader Account Resolution XXXX I was very disappointed when I asked for a superior I received someone with the same title. I told her my story and she would not help at all either. I again asked for a supervisor and she was even more defiant. After about 5 minutes of requesting a supervision she finally told me she would have someone call me back. 

In the mean time I took to XXXX to message them and post about my complaint on their page. I immediately received a response that they were sorry and would try to resolve the issue. I was told to email : XXXX XXXX then called me and said he would discuss with the higher ups and would call me back An hour later I received a phone call from : XXXX XXXX Servicing Escalation Specialist XXXX He told me same thing the others did that it was my fault and they would not change the credit report. 

I am extremely upset about this. I have not missed a payment with them in over 5 years and been an outstanding customer and over something I had no idea about and wasn't my fault they refuse to help me or even work with me. They claim to be # 1 in customer satisfaction well definitely not this time. 

I then reached out the the credit bureaus to see if there is anything they can do. They told me I can file a dispute but all that is going to do is go back to XXXX XXXX to verify if the information on my report is correct and we already know they are going to say yes. 

As a consumer I fell trapped and helpless. My score dropped over 50 point and no one will ever give me a loan with a missed payment on my record and I did not miss a payment. The payment came out of my account automatically like it does every month. I paid my bill! ( See attached ) I have no recourse because the only one that has any say or power over this is XXXX XXXX and they have made it clear they will not change this or work with me on this. So I am forced to accept this even though I feel it is completely wrong. I won't be able to get a loan for my new house all because of something I had no idea about. I have been working for years to get my credit repair and now all of that is down the drain because of this. 

PLEASE HELP!