Not sure about how things are programmed in your part of the world. I didn't even know that LG made a phone system. Your local telecom vendor, (if they are doing things well) may have a backup of the database that could be restored, without having to do hours and hours of programming.

The phone systems that I typically deal with have a location in programming that tells the lines where they are supposed to ring, that is not setup on the telephones them selves, but elswhere in the system. And different systems call it different things, so I can't say to go and look at hunt groups, or ringing line locations, or DID tables, or .... or .... or ....

I hope that gives you something to look at, but I would also call your vendor and atleast see if they have a backup and what it would cost to do a restore on the system.

The Cloud is just someone else's computer!