Dispute over partition of land

we initially bought a foreclosed property from the bank. the original owners then talked to us if they could just pay rent so they could still continue living in the said property. the property is originally 400sqm but the foreclosed land that we bought was just 200sqm. within the land there are 2 houses, it was sort of a compound for the original owners. after 7 yrs of their renting we decided to take the house so we could live in it. of the 2 houses inside the property the other house exceeds the boundary of the lot title. what can we do to settle the dispute? can they demolish the exceeding part of the house without our knowledge and consent? what can we do to delay the demolishing if they decide to do so?

is it possible to fence off your area? they are not supposed to demolish that portion if you do not agree to it and they do not have a court order.