Don't cancel. Let the system cancel, so that seller gets penalized.

As long as seller update the system, but never physically send the item, then I think you need to inform shopee to cancel already. Cos you must understand, once there is an update of tracking number, then it starts involve one more party. So shopee will be extra careful here, whether seller did not send or delivery company did not deliver. Anyway, when I say shopee... I mean the computer system. No actual officer will be going thru individual order and monitor them one by one... Buyer must report of any disputes. Only the computer system is monitoring, so you must alert them if have problem.

yes, system will auto cancel
i paid for something, seller said no stock, hv to wait few weeks and i agreed
i even click extend shopee guarantee for that order

but after shopee guarantee expired and seller did not key in tracking number, the order auto cancel
total how many days i don't remember dy

if didn't click extend shopee guarantee, it should auto cancel earlier, no???