cobra 3865

Got a alarm on a car and everything was great until someone
decided to press the button on the dash with a very small led attached
to it.

the car was running at the time no probs,infact the car has been 100%
reliable so when i tried to use it and it wouldn't go i know pressing
the button has buggered things up.
it bascially like the alarm has switched itself on and because i have
not got a alarm fob,i can't switch it off or reset it.
it also has battery back up as i thought disconnecting it
may reset it, but no the immobilliser has cut the fuel pump.

the car has its own rcl key that opperates a manufacturers alarm+immob
why it has a flipping Cobra i don't know

any ideas