Product: Mortgage

I need help with my Mortgage Company SN Serving Corporation as they are saying I owe over {$5000.00} post petition. Which is not correct. I originally was told last year that they never received my XXXX and XX/XX/XXXX mortgage payment. I send them to ( XXXX XXXX ) copies of the cancelled checks via email as well as mailed copies. I sent numerous emails to XXXX XXXX but never received a response back. 
My first email to XXXX XXXX ( SN Serving Corp was on XXXX XXXX, I never received a response back. I then sent another email to XXXX XXXX on XX/XX/XXXX and never received a response. To date, I never ever received any response back from her. 
I spoke to a person named XXXX XXXX ( SN Serving Corporaton ) and he sent me a spreadsheet and told me to match it up with my records as he would not tell me where this {$5200.00} post petition monies that I supposedly owe is for. I then was told that they didnt receive my XX/XX/XXXX or my XX/XX/XXXX mortgage payment. I sent XXXX XXXX an email on XX/XX/XXXX and attached a letter from XXXX XXXX XXXX to prove I paid them XX/XX/XXXX mortgage payment as they were my Mortgage Company at that time. He said the letter was not good enough and that I needed to provide a copy of the cancelled check. I then had to request a copy of my canceled check from my bank. I sent XXXX XXXX an email on XX/XX/XXXX and never received a reply back. I sent XXXX XXXX another email on XX/XX/XXXX and attached copies of my XX/XX/XXXX and XX/XX/XXXX canceled Mortgage payments. In that email I told him I noticed on their Spreadsheet that my XX/XX/XXXX and XX/XX/XXXX mortgage payments were applied to a Suspense account instead of my Mortgage loan and it said on their spreadsheet partial payment, which they WERE not partial payments. I paid what was billed to me. So they are definitely not partial payments. I also left him a voice mail message. I never got a call back or a response to my XX/XX/XXXX email or voice mail message I left him. I then sent another email on XX/XX/XXXX as well as called him but had to leave another voice mail message. He finally responded to my email but was very rude and not helpful. Said there were no adjustments that needed to be made and that if a partial or overpayment is made, it is put into a suspense account. I told him those were not partial payments and that those payments need to be applied to my Mortgage loan account. His response was all funds are accounted for which is not correct. Also the 2 months mortgage payments XX/XX/XXXX and XX/XX/XXXX, do not equal the {$5200.00} that they are claiming I owe in Post petition. He kept telling me to match my payments up with the spreadsheet that he sent me. If I supposedly owe this money, then they should know what this amount is for. XX/XX/XXXX Mortgage payment was for {$1100.00} and my XX/XX/XXXX Mortgage was for {$1100.00} which as you can see does not equal the {$5200.00} that shows owed under Post Petition on my mortgage statements. The late charges they have been billing me for only accounts for approx. {$400.00}. I would think that if I supposedly owe all this money that they would know in detail what it is. All late charges need to be cleared off as well. I can prove that I have never been late paying my mortgage. 
He said I also agreed to pay approximately an additional {$270.00} since they have approximately {$900.00} monies unapplied and that would clear up 1 months mortgage payment. My response was that I do not have extra money to send nor do I owe any past due mortgage payments. As I have been current on my Mortgage payments since I filed Bankruptcy Chapter XXXX in XX/XX/XXXX. 
He keeps saying there is no adjustments that need to be made on my Mortgage loan and that I need to pay approximately and additional {$270.00} to clear up the unapplied monies they show. That unapplied monies is from my XX/XX/XXXX and XX/XX/XXXX Mortgage payments that they put in an Suspense account instead of my Mortgage loan. I also noticed on their spreadsheet that they keep taking monies from the suspense account. Which of course reduces the monies that I sent for XX/XX/XXXX and XX/XX/XXXX mortgage. 
This will hurt my Bankruptcy Chapter XXXX discharge as they will claim I owe all this money which I do not. They also have been charging me late fees which needs to be cleared off of my account. 
I need help in getting this cleared up as I have exhausted all my efforts with them. Their accounting records are incorrect and are not willing to correct their mistakes. 
This has caused me so much stress and anxiety. 
I can provide you any proof that you need to clear this up. 
Please let me know if I need to submit any other documents. I am including copies of my XX/XX/XXXX and XX/XX/XXXX mortgage canceled checks as well as the spreadsheet they sent me I also have all the emails I sent both people if you need those. 

Thank you so much