Hi Arvind_C,
Thank you for posting your query in our community.
Based on your description, you want to refund a course in your Azure dashboard.
I really want to help you, however, because your query is out of our support boundaries, so my suggestion is to re-post a thread on dedicated Microsoft Certification category of forum. The members there are good at this aspect. You will get a more detailed and professional answer to your query there.
We appreciate your understanding.
Best regards,
Jazlyn