Road Right of Way

Good day. My grandfather bought a portion of land which did not have a road going in and out so he asked his cousin that he will pay for a portion of land beside his for road right of way. He agreed and gave a portion of his lot which is located of the left most side of his lot. His cousin's daughter was the one who knew and could confirm of the said transaction because she was the one withdrawing the payment which was made in an installment basis to pay for her education during that time. Now both my grandfather and his cousin has passed away. One of his cousin's children lived beside our grandfather's lot (it was inherited by my father) and that son of his built a concrete wall to dividing our lots. Only now did we discovered during a survey of the lot that the road right of way that my grandfather's cousin gave us was partly not his but most of the part of the said lot is owned by the landowner beside his lot. According to the survey only one meter of his lot was shown to be ours and the remaining 3 meters was owned by the neighboring lot. There is already a concrete wall built and the owner is already starting to build a building right beside the concrete wall. What do we do if the neighboring lot owner discovers this and claim their lot?

(Are you sure the land belong to the neighbour? )

It seem the neighbour noticed allready, because the wall is built covering part of your road. It seem the neighbour claim only the part he has built wall and house at.

Is it space enough at the COUSIN'S land to widen the road where it is only 1 meter? If so, you can ask/claim right of way there, because they got pay allready partly for land, which wasn't theirs, it was the neighbour's...