1) Open the "Carbon" widget in your favorite browser https://buy.carbon.money.
2) Select xDai from the Select Cryptocurrency drop-down. Type desired amount of xDai in the Amount input field.
Minimum purchase amount: $5 US
Maximum daily purchase without KYC (no identity verification required) : $250 USD
Maximum daily purchase with KYC (identity verification required): $2500 USD
3) In the You pay and You receive fields you will see the amount your card will be charged, Carbon's fees, and amount you will receive. Type Next and enter your xDai wallet address.
4) Enter your e-mail address and phone number in the corresponding fields. The service will ask you to type in a verification code. If you have Authy 2fa application installed for you number, you will receive the code in the app. If not, you will receive a text message with the code.
5) Select Credit/Debit Card in "How would you like to pay?" and press Next.
6) Type your card details and billing address details and continue with the payment.
7) In a few seconds after pressing Next, you will get xDai straight to your wallet.
Here is the transaction from the instruction on BlockScout, the xDai blockchain explorer. Check out how fast and efficient it was to settle the transaction. https://blockscout.com/poa/xdai/tx/0x52b634a2a7914eb59f835479e31a16030887187161ea5edb94e2441813af33a4/internal_transactions