Nationstar Mortgage Cant process payments without pushing you to late fees  Internet

My husband and I just today, (while we were on hold with Nationstar) went online to find out if anyone else was having issues with Nationstar Mortgage, and their ability to post a payment.  
Ocwen sold us to Nationstar beginning June 1st of this year.  Only 2 months with them I realize, but for the second month now they cant manage to apply our payment correctly, pushing themselves closer to being able to charge us a late fee, as they never received their "payment"  they only received "principal payments" 
They call our cell phones, they called on the 5th of this month (July, so the morning after a national holiday) to tell us we were late, because they hadnt received their payment.  However, they had received a payment, they received $1400, of the $1541 due for the month.  In fact, they received it in the early morning hours of the 5th.  Late, as I understand it, means after the 15th, not "we had a banking holiday and oh lookey there, its over in that pile of EFT's".  I then sent in an additional $160 which they received on the 10th.  But for the second month in a row, having only been with them for 2 months, they couldn't apply the money received to my payment.  Instead they, as they had the previous month, they posted both payments to my principal.  
Looking online, this seems to be a pattern, they post them wrong, then are able to charge you a "late payment" because they didnt received their "payment" by the 15th.  They only received "principal payments".  Then I can call them, argue for an hour be told yet again, that even though they have received authorization to speak to me, the wife of the account holder that they cant talk to me because I am not authorized.
I think that they are TRYING to tweak things so that they can charge people illegal fees.  Looking on the web, I see class action lawsuits, lawsuits won, complaints with your bureau, complaints with the BBB.  It seems ridiculous to me that this company should be allow to behave this way.  And I want to take a stand to make it stop.