suing after a short sell

we had a loan with HSBC, long story short, we had a modification with them. It was still to high of a payment. They told our lawyer and us we were going to have a much more resionable payment. after months of being told this they came up with they wanted 20000.00 in 3 weeks or they would foreclose. Instead they offerd us a short sell agreement, we took it and sold the house in 10 days. We know there was lies by the real estate agent and the home inspector, that could be proven. Our loan with HSBC we were lied to. We were told it was a 30 year fixed and it was a 40 year with a intrest rate of 9.67% topping out at 15.5% in December of 2009 our payment was going from 1500.00 a month to 1900.00 a month and then every six months it would go up till it got to 2400.00