Personal experience, ordered 2 cartons if A4 paper. Past the delivery date and no shipment notice made. Contacted sellers and did not get any response for another 2 - 3 days. Contacted shopee and the CS recommended I ask for refund by clicking that button. So, 4 days past the delivery I requested the refund. Then on the 6th day past delivery, someone WhatsApp me do I still need the items as they are planning to deliver next week? I said you should have responded to me via shopee earlier and not by WhatsApp. So another few days later, the money came back to my credit card.
So, it's really no big deal to have undelivered items. Ts may probably be new to Shopee or new in buying a $1,000 item the first time online... It shall be resolved one way or another...
I even bought miniPC from China and the HDMI port not working. As promised they paid for shipping back to China and sent me a replacement after. The surprise was, I told them S$50+ and they refunded me equivalent of USD50.
Recently ordered an item from pinduoduo and shipped me the wrong item. I requested for refund without shipping back since it's just a few yuan item. The refund was approved instantly. Come to think of it, I have check where the few Yuan returned to.
So just be patient and resolve with seller amicably.