I can't really see any subjunctives in your sentence, so it's probably fair to say that you haven't got it quite right. It's also not entirely clear what you want to say. Are you talking about one item or several? Your sentence is a mixture of singular and plural. Are you talking about a delivery that happened in the past? Or is going to happen in the future? Or deliveries in general? If you are talking in general terms, or about an item that hasn't been delivered yet, you could say '"When the items are delivered to you, you may find out that they aren't what you wanted "