Not Safe with ADT... System failed me. "TV is gone most of all my family and I are not safe"

We have an ADT alarm system in our house for safety during the day while we are away and at night while we are sleeping. I find it hard to understand as to why my alarm only went off after only sensing a ****** leaving my house through the window he opened and entered with... Was the alarm eye sensor not meant to pick up movement as they try to enter? I am not happy, They ran off with my TV and they alarm only went off as they were making a run for it, putting me and my family in danger.