Accenta8mini alarm.won't turn off. How can I fix it?

I have just moved into a new house and have a accenta8mini alarm. I have no manual. i tried to change the code but instead I isolated, omited 4 zones. When i tried to fix this the alarm just went off and would not switch off. The only way I could switch it off was turn off the power at the mains. Also the bell outside was sounding as well. Whenever i switch the mains back on the alarms starts off again. there are no lights on the panel and my code won't work, just constant ringing. Please can sombody help me urgently!