HAMP Problems with Citimortgage

My mortgage is through citimortgage. I participated in the Home Affordability Modification Program. I paid the three trial period payments on time. Submitted all required documentation. I signed and received HAMP contract with bank signature last November. Citi sent me 4 monthly statements through April 1, 2010. I have paid all monthly mortgage payments on time. By Mid April they started sending me default notices and stopped sending me statements with the revised HAMP payment. I have continued making payments on time based on the approved modification payment. Last payment was for October 1, 2010. I have called Citi over 50 times in the last 5 months to get this resolved, each time you have to talk to a different individual and give the the complete story again and again and again. They state that freddie mac unbooked the loan and that the booker has to rebook the loan. Nobody at Citi will take responsibility regarding the resolution on this problem. they just keep sending emails to the booker. What can I do to kick their butt into gear?

Also, why are mortgages bought in states where there are no offices of the bank buying the mortgage. Citi has no offices in Michigan. I don't have the opportunity to go into a local office with a 2X4 and whack someone along side the head. This practice should be outlawed by Congress.