I agree. After I did the test, I realised that it doesn't distinguish between nature and nurture. Yes, a person may have reacted to the questions in an INFJ way, but was that because their upbringing trained them to react, think and behave like that? Maybe, for instance, the extrovert in them got crushed somewhat — or a lot — during their childhood, or whatever. I can't remember what the “verdict” on me was. What I do remember is feeling a bit down about it and thinking — “I don't want to be that person!”
Shoulda, woulda, coulda — there's no
“should've” about it! There was nothing wrong with phoning them the same day. Sometimes we may decide to hang back and let something sit for a while, but who wants to live their life with all sorts of matters hanging around on a mental (or written) list waiting to be “sorted out later”? And, as you say, you weren't reacting to somebody telling you that you
had to do something — you simply decided that you
wanted to deal with the problem and do it straight away.
In fact, if you'd left it for two days, Walmart might have wondered why you hadn't contacted them about the missing items sooner, which could potentially have made things more difficult. So I don't think the lesson necessarily needs to be “I should have waited”. Maybe it's more about noticing the
quality of the urgency: “I want to sort this out today” rather than “I absolutely HAVE to sort this out today”. There's a subtle but important difference there, with the latter potentially creating a 'danger' message to your TMSing prone brain.
I'm one of those people who always wants to come up with and suggest a practical solution (even when people haven't asked me to — lol

). When I read about your Walmart troubles last night, I woke up this morning thinking, “I know what Patty could consider doing...”
You could perhaps tip the second delivery driver just a little less than you tipped the first delivery driver, then tip subsequent delivery drivers just a little less too, until you've effectively made up what you tipped the second delivery driver — and then go back to your usual full tip when you want to give a full tip for the drivers' good service. Not sure whether that's actually workable, though, as I'm a Brit and we don't have much of a tipping culture!
It is frustrating, but at the end of the day, it's not your fault that Walmart doesn't have a satisfactory way of dealing with situations like this so that the drivers don't end up losing out too much.