VAUXHALL FRONTERA 2.2 DTI 2000 X REG ALARM GOES OFF?

MY CAR ALARM KEEPS GOING OFF IF ITS LOCKED OR UNLOCKED.
ITS MENT TO STOP BY REMOTE SOMETIMES DO SOMETIMES STOP BY TURNING KEY STARTING IT HAS A COMPLETE MIND OF ITS OWN
TRIED OPENING CLOSING DOORS RESET IT THEN GOES OFF AGAIN SPEND HOUR PLAYING AND ANNOYING NEIBOURS
WHAT CAN I DO