1) Install SD Insight (free at Play). That'll give you an idea of what the card is. (Manufacture date - which can't be 1.1.70 - if it is you know you have a counterfeit card, manufacturer's number, etc.)
2) Install h2testw
on a Windows computer, use a card reader if necessary, and see what's in the card. If it was really a 32GB card programmed to claim to be 64GB (normally they'll use 2GB or 4GB cards for that), the program will tell you the real size of the memory card inside the SD card (which is more than just memory).
I know this is now moot for you since you sent the card back, but if you're going to buy SD cards you should have those 2 programs available first. (I went through a rack of "32GB" good "brand name" cards in a big box store. Out of 12, 2 were counterfeit. Even with a magnifying glass, we couldn't see any difference in the printing on the card or the packaging. But both "32GB" cards were 4GB memory chips.) If I buy a card, I pay for it, then install it and run SD Insight on it before I leave the store (and make sure I have no other SD cards with me). If the card is fake, I have a discussion with the manager or owner. They can strip-search me if they want (that'll cost them more than they make on cards in 5 years), but they'll refund my money, replace the card or the sheriff will execute the judgement I'll get in court against the business.
Counterfeiting memory cards should be
a felony. Unfortunately in most places it's just "give him another card". And that's why it happens - the loss/benefit ratio. If you get caught you don't lose anything. But you can sell hundreds of $2 cards for $100 and tell the people who don't know any better that their phones must have corrupted the cards, and they should get their phones fixed.
It's like the "antenna boosters" the industry used to sell (I refused to even deal with the people offering them to dealers) - the ones you pasted under the battery. They "improve" your - oh, not your, the seller's ... uh, bank account. They sold for $9.95 each. If the dealer wanted to really win you over as a customer, he'd take you aside and let you know that - and this was only for you - he'd give you the card for $5 - 50% off.
They sold tor $10/thousand - that's a penny apiece. And if you bought large lots - say $100,000 - that would cost you about $100. That's 1/10 cent each. For $9.95.
And they did as much to improve your signal as praying to Zeus does.
People only rip people off because the people who get ripped off allow themselves to get ripped off. If everyone who got ripped off called the rip-off artist out, we'd need a lot more prison space.
Oh, in the future, give yourself a fighting chance with SD cards. There are only 2 manufacturers (everyone else buys reject chips and programs what's still working to show) - Samsung and SanDisk. And, IMO, Samsung is too expensive for the same quality. So I buy SanDisk. So far I've had one bad one - I broke it trying to put it into a phone. It still works, the coating is a bit chipped. (I'm 71 and my eyes aren't what they used to be.) I'd bet 50/50 that SanDisk would replace it if I asked. And I buy retail, since I don't need many cards, so they never heard of me. But I've heard that they've replaced counterfeit cards that were made to look like theirs. And they rewrote their firmware (there's firmware in those little cards) to fix a problem that a phone manufacturer caused. Not their problem, but they put forth the effort to make their cards work in those phones. That's the kind of company I choose to give my money to, even if it costs a little more.