Homeward Residential Keeps lying to me Coppell, Texas

I got a letter from Homeward Residential that says they've been trying to contact me because I contacted them for help with paying my loan & want to modify the loan.  But, their number never showed up on my caller ID nor did I receive any correspondence from them.  When I told them I never contacted them for help making my payments & want an investigation, they refused to open a fraud investigation.

Also, when I called them about my payment for Feb 2013, I was told it is a little over $511. Then, on my statement, it said I owe $579.29.  I called again & spoke with a female rep in Jan 2013 who said my Feb 2013 payment is $556.25. Then I called a second time in Jan 2013 to make sure I had the correct amount, a rude & argumentative male rep said my Feb 2013 payment is $556.25. But when I go to pay it online, it says I owe $570.29 for Feb 2013. They say they sent me documentation of the correct Feb 2013 amount owed, but I never got it.