my house alarm keeps going off random and its doing my head in now, i can turn panel off but outside keeps going ! have took back up battery out also

the battery is a back up ,u will have to turn off the fuse box or remove the fuse in the power box and removed the wires in the panel to dismarm the alarm

Depending on the system you could have a battery in the siren box itself, so you can either disconnect this inside the bell box or wait for it to go flat.
If the mains is still connected to the alarm panel, it will just keep recharging the battery.