Hi,
First, please make sure your Developer support plan renewal is set to Off using instructions below. Once it has expired the monthly charges should stop.
In the Azure portal, please navigate to Cost Management + Billing using link below:
https://portal.azure.com/#blade/Microsoft_Azure_GTM/ModernBillingMenuBlade
On left, click Products + services -- All billing subscriptions blade. Click on context menu (three dots) to the right of the Microsoft Azure Support line and choose Change renewal setting.
In the flyout window on right, select Off and click Save.
The above will cause your Developer support plan to expire on the date shown and not be automatically renewed.
Second, please carefully follow my instructions below to create new billing support request without getting stuck in endless loop. Billing support is free. You can ask engineer for refund.
If you have issues creating ticket please let me know in a comment.
1. Navigate to this link to start the process:
https://portal.azure.com/#create/Microsoft.Support
2. Enter billing in the box and click Go
3. Select Billing and click Next
4. Select your subscription from the dropdown and click Next
5. At this point there will be a delay of several seconds, and then various options will be displayed. Click Create a support request button at the top. DO NOT CLICK any of the other options.
6. Fill out screen, Summary, Problem type, Problem subtype, then click Next button at bottom. You need to select different Problem/subtype than shown below
7. There will be another several second delay, and then some solutions will be displayed (this is similar to above). DO NOT CLICK any of the solutions, instead click on Return to support request button in upper left corner, similar to below
8. Now you are back at support case. Click Next button at bottom to continue to Additional details tab. Fill out information as required, one of the items you may need is your Subscription ID.
You can open separate browser tab and navigate to your subscription in portal, the ID is there, click the copy button to the right of it, then paste it into the box on Additional details tab. Click Next to advance to Review + create tab, then click Create.
You should receive an automated email within a few minutes and then be contacted by support within 1 business day.
Please click Accept Answer and upvote if the above was helpful.
Thanks.
-TP