I bought robux to xbox but i didn't robux it got error and charged me and i didn't get my...

This might happen due to a delay in processing your payment.

Try to remove your profile, then turn off the console and remove the power cord; wait for 1 to 2 minutes before plugging it back in and turn on the console and sign in!

Then, check if you received the Robux!

If the issue persists, you may want to contact the developer for further assistance!

You would need to talk to the roblox publisher. Here is a link to there help page that deals with your situation.

Roblox help page

But Will Roblox Ban Me for refunding the robux if I didn't mean to buy them thanks for your response

I purchase robux as well. My bank was charge but did not get them.

I bought a roblox add-on (400 robux) thanks to microsoft rewards, i recieved the email of the payment but didn't get any code (giftcard code i suppose) so i can't reedem it. What should I do?