i and my family own a piece and parcel of land in gujrat total area is 1 acre na plot we in 2008 sold part of the land to the other people via registered deed but the 7/12 extract is still in our name then in 2013 all the people approache us to cancell the said deed and they surrendered the said deed with us and allowed us to sell the whole land to any body then on june 15 2013 we entered in to mou with the builder for sale of the said land butt he builder failed to obey the conditions mentioned in the mou and then we decided to cancell the said mou by sending legal notice via advocate and issuing public notice but on receving the legal notice builder started harassing us that they will file fir aginst us under section 420 of ipc we sought explanatin they said that we have already sold the land to other people also thats why, but we had already informed him about that before signing the mou and now he is taking the advantage and harassing us pls help me and guide me now what to do even i had told them to take there all money back from me but they visited my advocate and are demanding 50% penalty