what brand is it?
dei ( viper, clifford, python)
code ( code alarm, prestige)
more info is needed to help you.
best thing you could do right now is find the brain and unplug it. this should take of your problems in the short term. that is If it was installed correctly in the first place.
if its dei get someone with a bit writer ( dei's programmer for your brain)
if its a code or prestige get a new alarm these things ALWAYS have fuggin problems.