But obviously there is no way, that buyer would not chargeback. But how does chargeback work? And why is it even allowed? on a gift card?
Yeah, TeamViewer should be a good solution for this. As for chargebacks, it's just how banks and credit card companies work. It's a type of payment dispute done by the card holder.
Suppliers who can gift cards in bulk though and sell them at a very low discount usually bought these cards using stolen credit cards.... so basically, the "chargeback" will occur when the original owner of the card take action (contact the bank, block the card, dispute all the transactions, etc.)
So if you redeem them the chargeback wont work?
It's actually when you use them that the chargeback won't do much to you.
If you redeem 100$ in your account for example and then order instantly, you're pretty much safe. However, If you're keeping the money in the account, the chargeback will work and you'll see that says "balance withheld".
I'm not telling that you shouldn't deal with OP as I have never traded with him and he could be trustworthy. If anything, and unlike digital cards, the physical ones like the one sold by OP, are much safer.