I have an omnicrom 7000 alarm system which has never been operative ?

I have an omnicrom 7000 alarm system which I have never used since moving into the property, however whilst hoovering I have cut into the wire. I do not know whether it is still live or not and I do not have any of the codes. I need to either disconnect it and /or replace the system can you please give me some advice as to the best way to approach this!!!