BK negotiation?

[sunnycali]

I received a letter from the trustee that I have to pay $50600 of excess equity in my house. Majority of the creditors filed the "claims bar date" and accumulated to approx. $60k. The trustee had told me in my second meeting that he was willing to make me pay half of the excess equity. I spoke with my attorney today and the trustee is willing to accept $40k but I think my attorney is not working hard to negotiate. My attorney has been lying to me along. Is their a possibity I can negotiate with the trustee to lessen the amount, maybe $20k? I'm preparing to write a letter to the trustee since my attorney is of no assistance.