Product: Mortgage

XXXX payment was posted by mortgage company per payment amount and additional {$100.00} for principal only. 

{$1500.00} normal monthly payment XXXX principal only {$1600.00} total payment Per that date the balance forward was {$250000.00} after the original payment was posted. And that was the correct application of the payment and principal based on the escrow application, the principal, and interest of {$1500.00} plus the additional principal of $ XXXXThat totaled the {$1600.00} I had authorized for them to withdraw from my checking account on XXXX. 

But because we have a dispute about Regulation Z and the grace period they backed the principal only payment out and brought the total to {$250000.00} in another transaction immediately following the correct application. AT this point in the totals for the account the principal I had asked to apply just disappeared in the totals. 

To further compound the problem they then reversed the principal and interest regular payment bringing the total back to {$250000.00} that had been the original beginning balance prior to the payment 's application on XXXX. 

The new transaction posted on XXXX they arrived at was {$1600.00} total payment per their new questionable total {$490.00} Applied principal {$780.00} Interest {$280.00} Escrow account {$64.00} Late fees they simply took. 

The new total was now {$250.00}, XXXX and that does not add right either at this point. 
A second transaction on XXXX described as a " curtailment with payment '' was posted for {$35.00} then brought the total on the account outstanding to {$250000.00}. 

At that point I went ballistic. I am a retired CPA and I know Reg Z and understand it perfectly. The vendor is always trying to tie the payment to the date they finally post the payment. That is incorrect and Reg Z discusses it quite clearly. The date I submit the payment is like them receiving the payment in a lock box and is the date late fees can be determined. I submitted the payment days before the grace period was met. So late fees with me were not valid and I fight them every time they try this. However, they took the late fees because they posted later than the grace period and we went to war. 

So on XXXX they did several reversals manually. I won the argument and they had to fix it. But in doing their adjustments they were overriding the systems and their calculations did not fix the problem. They brought the total outstanding balance back to {$250000.00} and never properly posted the principal payment I instructed them to make on XXXX during my online instructions. You can see the attempt to post the principal again but when you look at the total outstanding the manual override negated the actual post on the history. The totals are off. 

I have called them, written them many internal memos, done my best to communicate their error. My account is screwed up because of their incompetence. They never brought the balance back to the {$250000.00} in their corrections which was the proper application of the payment they posted originally on XXXX before they tried to take my principal payment and use it to pay their bogus late fee. 

I kept a record of their account history and my attempts to email them about this issue. I will not say I have been kind. I am furious that this has been so poorly done. They do not understand what is clearly evident if you know what should have been done. For me this is accounting 101 and these people are incompetent at best. I can NOT talk to their accounting staff directly. Everything goes through customer service and I want my principal refunded to me or applied correctly. And I am tired of asking. Any good auditor would spot this problem immediately, and I am a good auditor. 

We have been arguing about this for over six months now and I am fed up. Who do I have to go to handle this complaint. It is not rocket science but this company refuses to comply. 
And they have taken {$100.00} I paid in good faith and it has disappeared into their systems fraudulently. What do I need to do besides file this complaint?