Hi,
Thanks for reaching out to Microsoft Q&A.
I recommend you reach out to Azure billing and subscription management team by raising a support request. Here is the link - https://docs.microsoft.com/en-us/azure/azure-portal/supportability/how-to-create-azure-support-request to create support case.
FYI: Azure Billing and Subscription Management support is included in the Basic Support Plan without any charge.
https://azure.microsoft.com/en-us/support/plans/
Please create a New Support Request in the portal and choose Issue type: Billing Problem type: Refund request, then click Next. Once it shows suggested solutions, DO NOT CLICK the Request a refund button, click Return to support request in upper left corner as shown below:
Please do not forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.