Contract Sale of Property...

[ju_ju_bean5858]

This is the second time I have posted this question. Thank you to the one person who attempted to help me out. I have a little more to ask about this all now.
I am currently buying a house on a contract sale. The same guy I am buying my house from was selling me the property across the street from me too. Then I became aware of a mistake in our contract for the property across the street. He said he would have an amendment drawn up and sent to us to look over and sign. After waiting for 3 months we decided to give up on it and sent him, his lawyer, and the escrow bank a signed and notarized letter telling them that this mistake made our contract null and void. After 3 weeks of not hearing from him he all of a sudden wrote us a letter telling us that one mistake in said contract does not make it null and void. Many people have told me that it DOES make it null and void and I am just wondering if it is true or not. Please help me out if u can. The mistake was in the Lot numbers of this contract. Basically one of the lots we were buying wasn't even his...it was the neighbors lot. I now know that the contract would be considered null and void without an amendment fixing the error. But I don't know what to do next. I have not hired an attorney due to my financial situation. But I want this man to drop the subject of that other property and quit bothering us about it. He has continued to tell me over and over like a broken record that the contract is still in effect and we have to make our monthly payments. Should we just send them yet another signed and notarized letter telling them basically the same thing that we told them in the last one??

You should have somebody review the actual docs but a material error does mean that you did not actually agree.

His delays may also void it.