Cannot reconcile 174 UR5e accessory kits with 161 mounting adapters

Our separate accessory order specifies 174 matched kits, each with a mounting adapter, but receiving counted 161 adapters in the sealed outer shipment. The seller now says the quantity means pieces. I have kept the invoice, their per-kit contents confirmation and the receiving photographs together; redefining kit after delivery does not explain the missing 13 adapters.