Hey there, Billy NL
From the image you have uploaded, I can see that you are going through the refund portal on Azure. However, you have run into an error when trying to get a refund.
If you continue to face this error, please can you contact the Azure billing team directly through the Azure portal. You can sign into this here: https://portal.azure.com/#blade/Microsoft_Azure_Support/HelpAndSupportBlade
Once you have signed into your account, please create a support request by clicking onto 'Create a support request'
This will open the support & troubleshooting window for you. For the describe your issue box, please type "refund request"
Then select 'Billing' as your service option and click next.
Then select the subscription you have the resource attached to and click next.
Please scroll down to the bottom where it says 'Need more help'. You will want to click onto 'Contact support'
You will then need to click onto 'Create a support request' at the bottom of help and support.
This will allow you to submit a request to the billing team who can help look into what has happened and see if they are able to process a refund for you.
Hope this information helps,
Nathan