Unknown person using our building’s cafe. Should I be concerned?

There’s someone who keeps coming into our building’s foyer cafe who definitely doesn’t work here. They don’t badge in, they just walk straight to the cafe, order a flat white, and leave

I’ve been keeping an eye on this for about two weeks now. Same time every morning. No badge. No eye contact. Just coffee and gone.

I raised it with building security but apparently the cafe is in a “public access zone.” Today it’s one rogue coffee order. Tomorrow our cafe is overrun with outsiders sitting in our chairs, using our sugar.

Where do I escalate this?