land ownership #thru verbal agreement

Good Morning!Nagse-seek po sana ng advice regarding land ownership thru verbal agreement.Iyong una po kasing napagbintahan thru verbal din e hindi nakasunod sa napag-agreehan nila na magbabayad on one-year basis then nung benenta un land sa mother ko sabi nung nagbenta punan lang un kakulangan sa binayad nun first na napagbentahan, sa amin na iyong lupa,After po naming nabayaran,pinatayuan namin ng structure (House).then after 2 years bumalik un first buyer claiming na sila ang may-ari nun lupa.For your info po,un lupa po ay untitled lot at un pong uri na awarded by the Government without title sa real owner,nag-ask po kasi kami sa munisipyo at ang sabi e un land ay walang claimant before...Ngayon po un first buyer nakikipag-areglo ng Php.150,000.00 para daw sa tinayo nilang perimeter fence, which is unacceptable knowing na subra ang hinihingi nila compare sa actual price ng structure.Ano po ang dapat naming gawin?May karapatan po ba sila dun sa lupa?Nagwo-worry po kasi ang mother ko kasi kesyo me kamag-anak na malaking tao sa gobyerno un kabilang partido.
Thank you.

Yung lupa is practically owned by Government right? The first Claimant allegedly made the Earnest Payment? Then you just added an amount based on the Earnest Payment of the First Claimant who constructed the fence to secure the transaction with the Seller who asked you to do so? Now, you occupied the Lot and you actually enjoyed the privilege of the Earnest Payment of the First Claimant? My friend, I think by conscience you need to pay the First Claimant, this is truly unfair if you are on their position. You may need to settle this in Baranggay Level then hopefully arrive to "Tawaran". This is not a matter of Legality, this is a matter of conscience.

thank you sir