Well I can tell you for sure iPhone users don't ever have to deal with any memory card related issues. That's for sure.
I have to say, it's a bit unreasonable to demand Samsung replace a memory card or a phone. The phone you can just return of course, you're still within that remorse period, it's probably fine though. The card is most likely fine too, just needs to be reformatted. It's not just the phone, but this kind of issue can happen with any devise and any memory card, the lesson to be learned from this is to backup, and backup often. Unfortunately digital files are almost never covered by any kind of guarantee, I'm sure they have a fine print somewhere stating they're not responsible for this exact thing.
I use a SanDisk in my Note9, it doesn't have to be a Samsung card.
Why do you keep insisting it's non functioning? If it's formatted in the phone it should be just fine. Try it, save your data to PC just in case and then move it to the card. It should be OK, right? That's the like of reasoning that I don't understand. Other than some data that got corrupted, what else is wrong with the card?
Plus you seem to be convinced you found the bad link, but it might not be. Maybe it's Android that cause the data loss, maybe the memory card itself reacted oddly to the new phone or OS, maybe it was a coincidence, maybe it was removed unmounted (very likely because no one ever does it the proper way) and it caused the issue, maybe whoever was handling it touched some contacts and something shorted. We will probably never know for sure, the tech can act up sometimes. I don't have any issues with my memory card and the Note9, so it's not some widespread issue with it. If the card works once reformatted everything is probably OK, but I will repeat, back everything up just in case.
(I mentioned returning the phone if you think the phone is defective, I don't think it is or that it's a good idea, a non Samsung memory card is not their responsibility though)
