Sacalu

Thought I make my own post, maybe someone can help, plleeeaze!
I have Subaru Impreza 2001 wrx, which has Sigma alarm system.
A week ago friday I parked the car no problem, didn't need the car on wknd and went to start it monday and... nothing. Engine will not turn over. Also the flashing light on dashboard that tells you the alarm is working, has shut down. Keypad also has no light on it so can't do anything with it.
It has been parked on the same car park always with no problems so I'd rule out any interferrance.
I checked battery and fuses and they were fine,but was convinced by the local Subaru dealer it still is a battery problem so I bought a new battery yesterday, and...NOTHING!
Personally I think the immobiliser has locked the engine and then the whole alarm system has failed, dunno why though...
(I don't know if this is any relevant info but several months ago I dropped my keyfob and it broke, and since I bought a new fob, I haven't been able to get into the car with it, I've been using the key. When I do press the button on the keyfob, the light on it flashes, I think the fob would just need reprogramming, I have all the codes but as the system has failed, I can't type them into the keypad)
Biggest problem is that no-one here in Finland seems to have heard of Sigma alarms and won't even try to help, they want to remove the whole thing and put a new one on... FOR 900€!!!
Please someone help!!