Online ordering to kombini

I'm looking at ordering some things from an online shop in Japan, and getting it delivered to the kombini by where I'm staying (a Family Mart for reference), since ordering from them directly internationally is generally a hassle. However they're a second hand store (Suruga-ya) and are known for sometimes taking up to a week to send stuff out.

I was checking guides for kombini pick ups and am getting conflicting info about how long they'll hold something before returning it (one said 10 days, another 24 hours). My plan is to order about a week before I go and pick it up when I arrive, but sometimes they'll be quick about sending it out so it might arrive a couple of days before me.

Does anyone know how long it'll actually be held before returning?

I have not bought from that store, but when buy from amazon.co.jp for pickup at a convenience store, the email says they hold it up to ten days.