Veritas Alarm why thr constant beeping for a week inside?

I've been in my house 2yr and never used the alarm due to not having a code.
Well electric went off last week and I've had a permanent loud beeping from 1 the keypad and 2 the main inside alarm box day & night.
The outside alarm isn't going thankfully.
I'm awake at 3am asking for simple advice on solving this problem, before I us a hammer on the bugger.
I need basics due to patience now gone.
Thank you