I buy gold coins in Killer Instinct money written off but the coin did not come

help me to solve this problem

  1. Have you reset the game?
  2. If that didn’t work, have you reset the console?
  3. If neither worked, contact Xbox Support and they’ll attempt to help you, I believe.

Well, bud. I can’t offer any info to help solve this. However, I recently went through this same situation myself. All I can tell you is to contact your bank, get the transaction cancelled, and then try again.
Here’s the link to the forum topic where I detailed everything I went through on this:

If you are going to contact Microsoft customer support, I only hope you have better luck than I did. Just be sure you have a few hours to be on the phone. Just in case.

Not sure if it’s an option but I’ve always done all of my (few as they may) customer service interactions for Xbox Live through the online chat system. No problems thus far through that route.