@alhidell, I understand your disappointment and frustration. It's a familiar feeling so you can bet I've been there before, many times.
Always chasing the rainbow only to find I'm eventually back where I started from minus some money. Yes I know what they say about a fool and his money... but, you now know the score too.
We can't even call them a scam because if you read carefully they never actually promise any sonic improvements, do they? So they're not really lying are they? They might imply something, but that's not a crime is it?
Anyway, I would suggest re-reading this post by @jnorris2005 again. There seems to be an awful lot of wisdom in it.
"With all the snake oil available in the US, you ventured out to some unknown, unseen vendor a half a world away to get snookered. The operative phrase in your original post is " Decided to return because they were no better than several other cables I had on hand". Fortunately you've only been taken for $40, not the whole $100."
Might also be worth remembering that no one country has a monopoly on snake oil, or that no cable (at any price) can be shown to be any better than a pair of twisted iron coat hangers welded together.
As you said yourself, "they were no better than several other cables I had on hand".
Since there is no valid reason why they should be, not a single one, you can at least rest assured that your facilities are clear (despite any cognitive biases that might be working against you here).
Thankfully it was only $100, cables can cost vastly larger sums than that. You even got $60 back!
Personally, I'm more than happy to stop at the point of high purity OFC cable which works out a lot less than that. Some might say even that's overkill.
Ultimately, there may be some sonic gold at the end of the rainbow, but you're rather unlikely to find it by swapping the contents of your bank account into that of a cable supplier.
No matter where they're based.
https://www.google.com/amp/s/www.soundguys.com/cable-myths-reviving-the-coathanger-test-23553/amp/
