Four finger sets ordered, four individual fingers arrived

I can't decide whether to call this a short shipment or a disagreement about the order. We bought four fixture-change kits for our FR5 from a seller in China. Their last message says each kit includes a pair of gripper fingers; the invoice says four kits. The box contains four loose fingers and four mounting plates. Now they say fingers are counted individually. Which wording would you put in front of them first?