The seller is not disclosing the location of the sold property

I want to state that we have a plot of 165 sq. Yards. With the name of my mother. The plot had been purchased in 2005. We have registry document in favour of my mother. At the early time we visited many times but after two or three years means around in 2007 or 2008. We could not visit there for many years due to some circumstances. After a long time when visited my parents forget the location of the plot due to development in nearby areas In between we have done mutation against property. When we met that person who sold us that property to locate my property. He told us that he does not deal now regarding this property. He told us that regarding this property his elder brother XYZ will entertain. Then we met his elder brother XYZ. Now XYZ has been making us a fool for the last two years. He is not describing the location of our property. Now we have nothing in our hand except registry paper and mutation paper. WHAT SHOULD WE DO?