Can't reset alarm?

My alarm went off when my dogs managed to get out of the kitchen into the hall. My neighbour managed to get in and put the code in and alarm turned off.
When I got home The alarm had the red led on with the hammer symbol.
I put the code in again but it just beeps and red led stays on.
The alarm won't reset.
I've tried going into engineer mode and got the alarm to go off but when I come out of engineer mode it still won't set alarm.
If anyone's got any ideas?
Cheers