was going to respond exactly what Dan said
IMO its completely wrong. if its pure by accident that u had. one idea there was Kosherica on board then maybe... but I certainly would expect Kosherica to stick to their policy and only allow customers or you would have many people claiming they had no idea... Pesach programs deal with this all the time and its straight up stealing
well once your just davening there you get to use the shuls facilities, take a coffee, make a lchaim, take some extra milk for the baby etc.
I know people who run some of these programs. Some of them are happy to let people join as long as they ask, and others are just outright shocked again every year by the amount of extra milk and coffee they need to bring in for the "guests".
People really don't realize what effort and cost is involved. If you do need to daven there, ask and respect the answer.