Okay guys, long story short...

I locked my car (03 impreza wrx) using the key fob. As soon as I pressed the button, the car seemed to repeatedly try and lock itself, I could hear the locks clicking a hundred times a minute, and the alarm started to sound. I tried to press the button again to disarm the alarm, but the key just wouldn't work! Now I thought that the battery must have went flat in my key, so I disconnected the car battery, but the alarm sounded for a while after this till it eventually stopped.
I went today and got a new battery fitted in my key, but as soon as I connected the battery back up, the alarm sounded again. I tried the key in the ignition, tried to start the car, tried pressing the buttons, but nothing is happening apart from the alarm going off, and the locks repeatedly clicking!
I've read the manual on how to reset my sigma alarm code, but I'm not sure where to start. I have a 4 digit code in my subaru manual that I got with the car, but entering that never worked either!
So I cant get the alarm off or get the car started, can anyone help?!?! Pleaseeee!?!?

 

There is a sequence you need to do with the ignition as well when trying to use the code, not sure whar it is but I do remember you need to do it inside 30 seconds, you can also change the code.

There is a thread on here about it so try doing a search for it.