you might be able to get another line on your cell phone and use that for the alarm… that way the hamburglar won’t be able to cut the line before he steals your beefs.
O/T and a great read: McDonaldland - Wikipedia
Alarm systems need a standard phone line to dial out for 911 and location purposes for monitoring by ADT or whoever. No way around it however I do believe that ADT does have a type of wireless network type alarming so you don’t need one.