Product: Mortgage

Last year my mortgage was sold to Nationstar Mortgage. I have had nothing but problems with them since. My contract permits me to pay up to six months in advance. I am also permitted to make additional payments towards principal without penalty. When attempting to make additional monthly payments, Nationstar would never apply them as such, but rather would simply apply them as if I paid additional principal ... I always had to contact them to have the payment applied correctly XXXX yes, always XXXX and to have my next due date moved up a month. 
I am now paid up six months in advance and attempt to make additional payments towards my principal. Nationstar not only fails to properly apply my payments, but they take my additional payment from the bank, hold it in suspension refusing to apply it to my account ( increasing interest I will therefore pay ) and then send me notices that the additional principal payment is viewed by them as a partial payment and demanding that I correct this to pay additional funds to make a full payment or I may be reported to a credit bureau as being delinquent. How can I be reported as being delinquent when I am paid XXXX months in advance and am making additional payments towards principal? This is not a one time issue, this is ongoing every single month. Dealing with this company is a nightmare. Viewing your site I note more than XXXX complaints against this company in last few years. I also note more than XXXX complaints against this company XXXX in the last three years. 
It is my opinion that this company is engaged in criminal conduct. I believe they deliberately misapply payments to artificially inflate interest, or fail to apply payments so they can collect the interest on money held in suspense. I also believe they deliberately do these acts often times to frustrate people who pay in advance or make additional payments in order to harass and frustrate them for doing so. I believe it is their intent to frustrate customers to the point that they will not attempt to make additional payments so that Nationstar can benefit by collecting additional interest. I am attaching documents here to demonstrate that I am paid 6 months in advance on my mortgage. You will also note that on XXXX that I paid an additional {$100.00} on my payment to be applied towards principal. I received an email confirmation that my mortgage was paid and an additional {$100.00} towards principal. However, Nationstar not only fails to credit my account the extra monies I pay towards principal ( they hold them in suspense ), they send me notices stating that I only made a partial payment and I must send them more money or they may report me as delinquent to the credit bureau. I am submitting documents received from nationstar to verify these claims as well. Dealing with this company to have these acts corrected is futile and frustrating. These are acts of harassment, threats and theft ( not apply my money to my account, costing me more interest, holding my money in suspense where they collect interest on it XXXX. 
With the number of complaints against this company XXXX here and with the XXXX, criminal charges should be pursued against this company. These are not errors or mistakes but carefully calculated scams being orchestrated against their customers XXXX victims XXXX to obtain as much money from them as they possibly can.