Roblox Robux Purchase Not Received

I am writing regarding an issue with a Robux purchase that I made on the Roblox website using my mobile phone. On 4 April, from the United Kingdom, I purchased a package of 500 Robux, paying with my bank card ending in 7695, but the Robux have still not been delivered to my Roblox account even though a full day has passed. After noticing that the Robux did not arrive, I contacted Roblox support, but I did not receive any response or solution to my problem. At the moment I have paid for 500 Robux and have nothing in my account to show for it. I kindly request that the 500 Robux I paid for be delivered to my Roblox account as soon as possible, or that Roblox provide a clear explanation of what went wrong and how it will be resolved.