Jodi,
For better or for worse, here are my thoughts:
My guess as to why that manager seemed so uncomfortable, is that he felt confused and very uncomfortable, apologizing for something that really wasn't his fault, after someone at corporate headquarters ordered him to do so.
You have to understand that Walmart is not your typical, run-of-the-mill corporation. It's more like a military operation, and corporate management is as secretive as the CIA, (and probably better organized). The company is extremely regimented. All their board meetings, their planning, their internal policies, internal memos, etc., are closely-guarded secrets, and anyone responsible for security leaks is promptly dismissed. They publish all sorts of PR statements, but they never divulge what they are really thinking, nor their true reasons for doing anything. This is all well documented, if you read the Wall Street Journal. Of course, many/most corporations follow similar policies, but IMO, Walmart has the technique perfected - it's one of the reasons why they are so successful. They do it better than any other company in the world.
Therefore, that manager was not at liberty to reveal where he got your phone number, (my guess is he got it from corporate headquarters, of course), and he had to be very careful about what he said, (if he wanted to keep his job). The reason it wasn't his fault, is because corporate headquarters controls all the operational policies of every store, so he had nothing to do with the reasons why those "associates", (employees), behaved the way they did - they did exactly what corporate policy dictated that they do, and the store manager is required to support and enforce those policies. Put yourself in his shoes - you would feel as if you were in a bad dream, with your boss holding a gun to your head, forcing you to apologize for his, (your boss's), mistakes, while insisting that you admit no wrong-doing. That's probably why he seemed uncomfortable, detached, and insincere.
Thinking about this, I'm just making a guess here, but I would be very surprised if managers are allowed to make exceptions to rules, unless someone's life or limb were in clear and immediate danger. Look at it this way: Dealing with Walmart is much like dealing with the military. If you step onto, (or drive into), a military base, then as long as you are on that base, you have to follow a different set of rules than you were following everywhere else. While on that base, you must follow the rules laid out in the Pentagon, and no one on that base has the liberty to waive those rules for you, or anyone else, unless someone's life or limb is in clear and immediate danger, (and if national security is at stake, then danger to life and limb may not be a justification for exceptions, either).
If you were dealing with a "Mom and Pop" shop, it would be an entirely different matter, because "corporate management" would be right there in the store, and dealing with such a situation in a face-to-face encounter, is much simpler. With Walmart, however, corporate management is "faceless". Also, remember that you are dealing with the low-price discounter of the world, not Bloomingdale's. They didn't get to where they are by throwing money around, nor by spending money on great customer service, (every store has zillions of checkout lines, but every time I go to one, there are long lines, because only a handful of checkout stations are open, for example).
I'm guessing that an "uncomfortable" apology by the store manager, and a $50 gift card, are about the best that can be hoped for, in such a situation. Hopefully, that will pay for most of your clothes that were ruined. I honestly believe that it would be unrealistic to expect an apology from bottom-tier "associates", for the part they played. They had no choice - they were just following corporate policy, and they had no authority to "bend" the rules. Also, for what they are paid, they certainly have no incentive to take any chances that might cost them their jobs. All this is just my opinion, of course, but as far as I can determine, it's a reasonably plausible picture of the situation.
One other thing to keep in mind is that each and every one of us assumes that same risk, if we choose to leave our homes, when we are reacting. Of course, we assume that if we are in a store that has restrooms available, then we should be able to count on them, if we should need them. The question is, how far should a place of business have to go, to "guarantee" availability of such facilities, under extenuating circumstances, (such as when the facilities are being cleaned, repaired, or whatever). The restrooms are a convenience, but not necessarily a "customer right" under every imaginable circumstance. (Or am I misinterpreting the law?) "Stuff" happens, and as much as we hate to see it, sometimes we are just in the wrong place, at the wrong, time, and our luck runs out. Been there, done that, and as unpleasant as it is, sometimes it happens, and when it does, I usually attribute it to just plain bad luck, and hope that my luck improves in the future.
Love,
Tex