@WimModdejongen-7149 Greetings!
Sorry for the inconvenience caused to you. Please carefully follow the instructions below:
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:
Click Next, continue filling out information, make sure your email/phone are correct, and finish creating the case. A support engineer will assist you with your refund request. The ticket enables you to work closely with the support engineers and get a quick resolution to your issue.
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/
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