ISV (Independent Software Vendors) and Startups: A Microsoft program that helps customers adopt Microsoft Cloud solutions and drive user adoption.
I think a manual billing review is the next step. Go to Help + support → All support requests, show closed cases, and select Reopen request. Include the invoice number, explain the YC credit misunderstanding and financial hardship, and request a one-time waiver. If reopening isn't available, file a new billing case referencing 2610140030005259.
If ur credits came through Microsoft for Startups, Get program support can also coordinate a refund review with the billing team. Approval isn't guaranteed.