Product: Debt collection

I received multiple ambiguous notices from a Mr. Cooper that apparently is a name brand for Nationstar Mortgage LLC. stating " Welcome to Mr. Cooper! Effective XX/XX/XXXX, Mr. Cooper is now the servicer for the above numbered mortgage account. '' The above " loan number '' was XXXX. THIS IS NOT A LOAN OF MINE ... 
Another letter with the same date as the welcome letter stated : " The servicing of your mortgage loan is being transferred, effective XX/XX/XXXX. This means that after this date, a new servicer will be collecting your mortgage loan payments from you. Seterus, Inc. is now collecting your payments, Seterus, Inc. will stop accepting payments received from you after XX/XX/XXXX. 
Mr. Cooper advises me to " put loan number XXXX on my check or money order made payable to Mr . Cooper. '' Another letter states that Mr. Cooper " ACQUIRED '' the loan from XXXX XXXX, when XXXX XXXX had already disclosed they had no interest in the loan Seterus Inc was trying to assign to XXXX XXXX. 
Errors -- I have never made payments to Seterus, Inc., Seterus Inc. sent letters to my home and advised that they were servicing a loan for XXXX XXXX when a direct response from XXXX XXXX stated that XXXX has no interest in my property. Seterus tried to get me to put loan number XXXX on checks and money orders and send to Seterus. 
I have sent 2 QWR 'S to Mr. Cooper/Nationstar advising them of their error and no response was received to the first letter. Today I get a letter of NO RESPONSE from Mr. Cooper first stating that they responded to the 1st letter which is false. But the second letter 's response is this -- '' We looked into the concerns you expressed and after an investigation we're sharing with you what we found : Under RESPA AND Regulation X, Mr. Cooper is not required to respond to requests for information that are duplicative and substanstantially the same as previous requests. '' The XXXX XXXX Mr. Cooper included in their XX/XX/XXXX response that was never received by me and given the information in the XXXX letter I doubt it was sent, the XXXX letter provided no information other than the information requested and errors cited is " considered outside the scope of information that must be provided, is proprietary and confidential. '' The XX/XX/XXXX response was total rubbish and fails every aspect of RESPA / Reg. X for a proper response. 
Mr. Cooper however included a litany of old mismatched loan files from a previously rescinded loan I had with XXXX that had a loan number of XXXX. XXXX # XXXX if Seterus or Mr. Cooper were to check what is obviously a hodgepodge of junk records still being peddled to junk buyers they would have found in court records a payment transaction record for loan XXXX and see that loan was fully paid XX/XX/XXXX with {$130000.00} applied to principal and {$4100.00} being applied to interest. I recently secured another copy of the account ledger for loan XXXX and the payment is still reflected on the account. 
Mr. Cooper did not attempt to investigate and did not intend to perform any amount of due diligence. Just a side note as to this terrible practice of creating new loan numbers to harass homeowners and hide an enormous amount of wrong doing within the mortgage industry the contract does not provide for the requirement that a homeowner identify any other loan on their payments. This ill-conceived practice of switching loan numbers for homeowners to submit payments is reckless when homeowners are already wrestling with WHO to pay as that entity is ever changing. Switching loan numbers is not in line with the cradle to grave ID numbers for mortgage transactions. Transparency is needed. I have no loans identified by XXXX for Mr. Cooper and I did not have a loan identified by XXXX for Seterus. Could these newly created loan numbers without newly created loan transactions be the reason for Nationstar D/B/A Mr. Cooper is have so many regulatory issues with incomplete files and data.