Mall Jewelry Store Alarm System?

Hello! I am not a security professional, however I would appreciate some advice from someone who is. I currently work in a small, family-owned fine jewelry store in a mall, and recently my coworker and I are concerned that we may have people casing us. Very suspicious individuals have come in on days when we work alone, and while we never discriminate here, they have a very particular way of phrasing questions that tends to give them away.

My question is this: Is there anything we can do that would protect us more effectively than a regular panic button? We’ve tried calling Mall security, and despite the fact that we are the only fine jewelry store in our mall and easily the store with the most expensive goods, aside from one electronics store maybe, it takes them an hour to get here when we call them! Sometimes longer! If we were being robbed, they would be completely useless. One time we did have a theft incident, and the mall security couldn’t be bothered to come in time to actually identify the thief and have them removed.

Is there a better security system that we could implement? We are starting to feel like sitting ducks here.