Roblox Robux Purchase Went Through but Never Showed Up in My Account

Today, at around 8:18–8:21 PM, I made a payment of approximately $3 by credit card to purchase 200 Robux. Despite completing the transaction, my in-game balance never increased and the Robux did not appear in my account.
I have not yet contacted support regarding this transaction, and I have not received any SMS or notification from my bank confirming that a charge was made. Regardless, I was left without the Robux I paid for and currently have no information about the status of the payment or where the Robux ended up.
I am requesting that this transaction be urgently reviewed and that either the 200 Robux I purchased be credited to my account in full, or that if any charge was processed, I receive a complete refund.