ASC is being verf difficult, what can I do?

I have called and called ASC numerous times to get them to work out a payment program. They tell me things like the computer is down call back tomorrow. I call back and I get another excuse and when I have asked if they have record of my last call yesterday they tell me I never called. I was served with papers 12/10/07 and even though they received my payment of $2000.00 on 12/07/07 that would have caught me up in my payments. They told me because of the notice they would be sending back the $2000.00 I have yet to see that money back. I was told on the 12/11/07 by one Rep. that they were holding the money in suspense while we would see if we qualify for a repayment program. The next day I get a call from the foreclosure trustee stating that ASC was sending the money back because they (the trustee) couldn't start the foreclosure proceedings when I had just caught up my payments? I called on the 12/12/07 I was told indeed that the money was being sent back to me and that I could fax in all my monthly expenses to see if I qualified for their program. I was called by the Trustee on the 13th and they stated that to stop the judgment that I could pay $9600 on Dec.26th that would bring my account current and pay the attorney's fees. ASC has lost payments that I have made and told me that I couldn't make partial payments they only except full payments above my total monthly payment. They wouldn't work with me on finding the supposed lost payments. I have faxed in copies of my bank statements . Ever since ASC bought our contract from Mortgage Lenders Network it has been a living nightmare. I am 2 months behind on my payments according to my bank statements. But with the supposed return of my Dec. payment that makes me 3 months behind. How can they legally state I am 90 days delinquent when I'm not?