Car Alarms: Alarm keeps going off., awkward times, hazard light

Question
Hello,
I can really use some advice here. I have got an Audi A4 2002 (later shape) 2.5TDi.
Its been about 3 months since the problem started. Before my alarm used to go off at awkward times with the hazard light aswell. When the engine was hot it wouldnt go off till the engine cooled down.
I found out from the audi dealer that they have to do a diagnostic check first which would cost me £150 and who knows what the actual repair would cost.
As I am short of cash I didn't do anything about it. So I lock my door from inside leaving the drivers door open (not remote locking it at all).
Now what happens is even if I lock it, it would go off after a bit, and the hazards lights dont come on anymore. And the worst part it, now the alarm even goes off when I am in a long drive.
So please can anyone tell me how to solve this problem of mine without spending too much.

Answer
Hate to say it, but on this problem, Audi needs to
diagnose the issue and correct it. There's not alot
you can do to fix this yourself unfortunately.

They need to point out the problem, and then
repair and reset it.

Sorry, but can't fight the logic here.
Suck it up, spend the pounds and have them
look into this for you. Then that's one less
thing, right?

Best advice I have here.

Good luck.

ALARMTEK