Not Receiving Humble Choice Refund

Most likely your money is stuck in the payment system somewhere. It may take up to ten days for your money being returned to your bank account.
Until then: keep calm and don't panic.

Also, we're on Sunday, customer support often doesn't work or goes molasses paced on weekends.

For India it takes 7 to 10 days for humble bundle refund to reflect back in bank account.

You can use that information (HB saying they didn't charge you) to request a refund with your bank, I had the same problem with Nintendo and I had to contact my bank, they solved it really fast, but the money took 30 days to get refunded.

Of course, first contact HB support and let them know they did charge you, just wait for their reply.

Humble support is terribly slow for some reason, my support ticket took over a week to even get a response.

I've contacted support recently too and didn't get a response from them. I am still waiting and it has been a week.