Abbey alarm

my daughter as just been away with us she had a pitch next to our season pitch she as a abbey 520 2005 i was in bed when i heard her alarm going off at at one thirty but only for a few seconds then again at two but this time it never turned off i went outside to find my daughther in tears she had discontected the battery the 240 volt but still going off so i got my torch we alocated the alarm box unscrewed from floor discontected the wiriing but still going off so we wraped it up in a quilt and  took turns on sitting on it so no one could hear it we was like this to 9 in the morning when my wife came into our daughters caravan to see if she had seen me my wife had slept through it all my said show her the alarm box with that she found the on off switch on the bottom