Use your Azure account credentials to sign in to the Azure portal.
Once signed in, go to the left-hand menu and find the "Help + Support" option. If you can't find it, click on "More services" to locate it.
https://learn.microsoft.com/en-us/azure/azure-portal/supportability/how-to-create-azure-support-request
Click on "Create a support request" to open the support request form.
For billing-related issues, select "Billing" as the issue type.
Provide Issue Details: In the form, provide a clear description of your issue. For locked invoices, mention that your invoices are locked, and you need assistance with unlocking them to proceed with the payment. Be sure to select the correct subscription and include any additional information that may help the support team understand your issue.
Billing and subscription management support is available.
https://azure.microsoft.com/en-ca/support/create-ticket
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