I attended XXXX XXXX of XXXX from XX/XX/XXXX-XX/XX/XXXXI took out XXXX private student loans to finance my education. 
My loans were initially serviced by Nelnet with no problems. 
In 2014 my loans were service released to Firstmark Serviceswhich is a subsidiary of Nelnet. 
I remit payments through XXXX XXXX Online Bill Pay making one payment of {$420.00} monthly. 
The servicer would split the payment and apply funds to each loan. 
I made 10 payments to FirstMark with no issues. 
The 11th payment was only applied to XXXX of my loans. Reason being is that the payment processing computer now can not distinguish between due dates and my entire payment was applied to the first loan coming due. 
I was told by customer service that, due to the due dates being off by one day, XX/XX/XXXX and XX/XX/XXXX, that the payment was only applied to XXXX account and that she could not make the date the same for both loans due to different banks holding the notes to my loans. I was told to send my payment to a different address where a human would apply the payments to my individual loans. I did this for my XX/XX/XXXX payment, submitting it XXXX XXXX, and it mysteriously disappeared for over 2 weeks before it was miraculously discovered on XX/XX/XXXX XXXX and backdated to XX/XX/XXXX XXXX. I would like to add that the payment being found coincided with a rather nasty email I sent Firstmark on XX/XX/XXXX XXXX. Since this date I have mailed XXXX additional payments to the address listed on my statement and thus far both payments have been applied only to the loan that is due on XX/XX/XXXX. I have called and emailed Firstmark and they have shown no interest in correcting this problem. It is my opinion that Firstmark created this problem in order to hinder myself and others in making loan payments. I believe this because the 10 prior payments the computer correctly and automatically split my payments among my XXXX accounts. Why would a servicer change this on purpose? To create more work on the student loan payer by making one have to call or email the servicer each month to have ones payment applied correctly? This is a major waste of my time and is causing undue stress in my life. I also believe, if I failed to call, this error would not be discovered within 30 days and then my credit would be irreparably damaged and thus I would be damaged monetarily.