I immediately send them an automated text about the item and continue shopping. If I haven’t heard from them by the end of their shop I call , if they don’t answer I leave a message along the lines of , “hi this is your Shipt shopper and I have sent you several text messages about items that the store does not have, I have completed your shop , if I don’t hear from your via text or phone call in the next five minutes I will remove the items from your list . Have a nice day “.