sined under false circumstances

i signed quit claim in order to have loan refinanced (and my name taken off) after i signed i found copy of deed with a filing date. i was told by co-owner who is now x-boyfriend that the original quoted rate was going to be higher so he couldnt refinance .he should have tore up the deed but saw this as a perfect opportunity to take advantage of me and my great credit that helped get a lower rate to stat with.