Neighbours leaving cat out while they go on holiday

Last time they went away, it was cold and wet. They got a friend to leave food in the garden for the cat but other cats could have eaten it. They don’t have a cat flap.

They are going away for two weeks and leaving the cat out again. I think it sometimes comes in through our cat flap to eat our cat’s food. If challenged they just say that a cat will always find food.

Our cat is extremely pampered so I don’t know if I am over reacting.