Fidelity ADT security... not secure?

We were away from home. Our home alarm went off. A neighbour let us know. ADT didn't call. We asked a family member to go and check and reset it. They phoned while our family member was there to say that the patrol vehicel had gone to check at the exact time our family member was there... family never saw a patrol vehicle even while standing in the driveway. Disappointing.