Car been sold with LTO alarm

Good day po. Ask ko lang po sana kung paano gagawin. Nakabili kasi ako ng 2nd hand auto from a friend last May 1. Wala naman problema nung una. Then nung ipapa-renew ko na, may lumabas na alarm sa LTO. So sinabi ko sa kanya na may alarm pala yung binenta nya sakin. Thing is, hindi nya rin alam na may alarm since napa-renew pa nya yung auto last May 2015. Nabili nya raw yun last April 2015 din.

Pinacheck nya sa kakilala nya sa LTO ang sabi isinangla pala yung auto ng original owner. May civil case daw yung owner kaya naka-alarma yung auto. So malamang ngayon lang lumabas yung alarma. 3rd owner na sya, bale 4th owner ako. Deed of Sale is open pa, wala pang notaryo maski isang previous owners. Tine-trace pa namin kung paano naisangla ng orig owner samantalang nasa amin yung original CR/OR, and napa-renew pa nung pinagbilhan ko last year na walang alarm. Sabi nung nagbenta sakin i-trace daw namin yung previous owner hanggang sa orig owner para maayos yung alarm sa LTO.

In any case, is it legal na magdemand na lang ako na isauli na lang yung bayad and then isauli ko yung auto sa nagbenta sakin? The deal was not made in good faith kasi since usapan namin is malinis ang papel and wala syempreng alarm (recorded thru FB chat).

Thanks in advance po!