Suing mortgage company

Hi, we bought our house 11 years ago w a no-doc mortgage. For 3 years I've tried to modify the loan/or the high interest rate to no avail-the 1st company(National Mortgage) went out of business, when they sold us to Ameriquest our escrow was gone & a lot of important pages of the contract were also "unavailable"- National, definetly changed income amounts to get us this mortgage. Two days before we were to close on the house, we were informed that we needed over 35,000.00 extra to get into the house-Then when sold to Ameriquest, they actually (offered repeatedly) to refinance when they got us. So now we have Citi & they've gone out of their way to offer no help to the self-employed folks. Wrong fax numbers, missing documents(I have all the fax info that went through-also, appparently, every 2 weeks the representatives change!)~Help! 3 years is a LONG time to do this-what can I do? our interest rate is 6.9%! thanks, Kris in CT -if National Mortgage didn't chnage the numbers from 40,000(income) to 80,000., we never would have gotten into this house.