Product: Mortgage

There are XXXX separate loans on my XXXX adjacent lots, although the houses share a common wall and utility easements. Nationstar mortgage has both loans. Loan # XXXX is in foreclosure and we are close to a loan modification agreement after 4 years of Nationstar running out of time and losing documents. 
The other loan # XXXX was modified in XX/XX/XXXX and I have been making payments on it, always one month ahead of schedule. 
XX/XX/XXXX, I changed my insurance company and my payment went up a little. In XX/XX/XXXX Nationstar recalculated my escrow payment and came up with a shortage of {$1300.00}, including {$420.00} for minimum required balance. My new monthly payment effective XX/XX/XXXX would be XXXX. I sent Nationstar {$500.00} in XX/XX/XXXX to reduce my escrow shortage and they returned my payment, having mistaken it for a payment on the loan in foreclosure. I called Nationstar consumer representatives and resolved the issue and made the {$500.00} payment to lower my escrow shortage. Later I discovered they had applied the payment to principal by mistake. 
My statement for XX/XX/XXXX was for only {$1200.00} because the new payment amount was to begin in XX/XX/XXXX. I paid {$1300.00} in XX/XX/XXXX for XX/XX/XXXX 's payment. 
Still waiting for Nationstar to recalculate my payment with the new escrow amount, I paid the new amount of XXXX in XX/XX/XXXX for XX/XX/XXXX. On XX/XX/XXXX, I made another payment of XXXX for XX/XX/XXXX. All my mail, including a birthday card for my son in law and my bills, was stolen from my mailbox XX/XX/XXXX so, on XX/XX/XXXX, I made another payment of XXXX for XX/XX/XXXX. I always stay a month ahead in just in case something like this happens. 
Nationstar sent me a letter on XXXX/XXXX/XXXX, saying that the XXXX I had paid in XX/XX/XXXX ( for XX/XX/XXXX ) was being held in " suspense '' because it was n't for the full amount. ( The bill was {$1200.00} and I paid {$1300.00}. Then the second payment I had made for XX/XX/XXXX was not processed until XX/XX/XXXX which made it a day late and, because my {$1300.00} payment had not been accepted, there was a late payment fee and two months payments were due immediately. I would never be late on a payment because I really want to keep my properties, so I called the representatives again. This usually requires hours of wait time and being shuffled around and calling repeatedly. 
During these hours, it came to light that the {$500.00} payment I made to lower the escrow shortage was applied to principal as was the {$1300.00} XX/XX/XXXX payment made in XX/XX/XXXX. 
Nationstar corrected all this, figured out m new payment amount of {$1300.00} and I am now, once again in good standing, ahead one month. 
Except that On XX/XX/XXXX, I got a letter rejecting a new loan application to replace loan # XXXX, a loan I had never applied for! Then my statement sent XXXX XXXX for XXXX XXXX, XXXX shows that the payment is {$1300.00}, including a late fee and an overdue payment fee. My XX/XX/XXXX payment was made XX/XX/XXXX and I just made another payment for XX/XX/XXXX. 
I do n't know whether Nationstar is just inept or if there is an evil intention here to nullify, by any means possible, my modified loan. I really need some help. 
Thank you for investigating this situation. I am just trying to hold onto my property as I am old now and this is my life 's investment.