IndieGala [shady practices]

Contact support and they will fix it for you. They're not shady, and they're an authorized store. They're just incompetent.

Assumptions much? Give them the benefit of the doubt, and contact them first, or you may be libel for shame-face.

If you don't see your paypal transaction on your paypal account, something else is wrong and it has nothing to do with indiegala themselves. So the issue seems to be with paypal, unless you missed something. If the transaction in your bank says "PAYPAL Indiegala SRL" or whatever then it's paypal that failed you by not showing the transaction, although I think this is just a misunderstanding.

They shouldn't be able to get straight to your bank and skip paypal. I mean, they can't. That's the whole purpose of paypal. You also could've paid with your card information before and opted to save it and went with that by mistake and didn't notice it, and then maybe the transaction failed and you weren't actually charged, it just shows on your card as a failed transaction for x amount. Check again.

I've had issues with indiegala giving me the wrong keys for games, already used keys, and I honestly despise how slow their key reveal system is, but it's alright otherwise, it works. It's not like humble or fanatical never had a problem.

If you think IndieGala is a 'useless grey/black market seller', why would you buy from them? Seems a bit counter-intuitive.

Sounds like the normal Humble Bundle practice of selling more keys than they have available.

But could also be a simple system failure.

Best to wait for support to give you a reply.

If it takes more than a week, blow them up on social media.

HB can sometimes take MONTHS to over a YEAR to get new keys!

Usually confirmation of purchase comes a few minutes after payment, not immediately.
Either you are very impatient or you have some problems.
If you have some problems on a site, it usually makes sense to write to support there on that site, rather than on any other. They have support both on discord and via mail. There is even one on the forum, but this is definitely the longest option.
They are an official seller.
It is strange that you think otherwise, but go to them to buy.
Yes, they have problems from time to time, but the support team fixes it in a few days.

Actually that's a problem they've had for months. When I try to pay through Paypal either the transaction fails immediately or it seemingly goes through just to receive a mail a few minutes later telling me that it failed and the money to be sent back to my card (this can take about an hour) as the transaction gets cancelled.
Only way for me to buy from Indiegala is to pay directly with my card. Although to be fair to them support usually solves any issue I may have within a few hours, they're quite helpful even if their system is a mess.