Just to piggy back off of what Tina said:
To the best of my knowledge, most paypal backers have gotten some sort of email confirmation. I know for some it took a few hours to show up in their inboxes, however. In your case, the email may have gotten stuck somewhere?
I know it's a cliche and you're probably going to hate me for saying it, but have you checked your spam filters? I have at least one other Kickstarter I've backed where about 90% of what they send me ends up in my spam, despite whitelisting them. It's super annoying.
The whole Backerkit thing was a bit of an issue for the devs as well, so I understand your frustration there. It's a pretty common tool that many Kickstarters use for managing Backer data, but it wasn't allowing RTG to do everything they needed to do, which is part of why there's some confusion.
If your information is in Backerkit and it is displayed correctly there, then they definitely have your purchase logged.
If you're very concerned about it, you can always reach out to RTG directly through their Support (at) redthreadgames.com email address. With the crunch time upon us, I'm not sure how quickly they'll respond.
has also been checking in semi regularly, so he may be able to shed some additional light on things the next time he does.
Lastly, as anyone else who was waiting on the great data export tried to link up their Humble yet? That might answer some of the other questions we have.
Again, totally understand your frustration, Moldavia. Just trying to do everything I can to help!