[mothered]

carrier confirmed the item has not fallen during transportation they won't issue a refund.

Ask them how the carrier confirmed the watch remained Intact throughout the entire journey of travelling through their network from consignor to consignee.

And if I continue to contact about the item they may not reply in the future.

Really?

Since when are customers/buyers not permitted to enquire about discrepancies with their orders? Tell them exactly that, and to refrain from replying with such nonsense. If their behaviour remains unchanged, be sure to get their details (full name, job title, etc) and say you'll forward a complaint to senior management about how you've been treated.