How can a Microsoft for Startups user escalate unexpected Claude Marketplace billing?

I have approximately ₹9.49 lakh of Microsoft for Startups Azure credits remaining. I deployed Anthropic Claude through Microsoft Foundry and later received invoice G183537293 for ₹70,716.76 because the Claude Marketplace usage was not covered by the sponsorship credits.

I understand the eligibility rule now. My question is about escalation.

Azure Billing has told me Marketplace adjustments are handled by the publisher. Anthropic has told me Azure Marketplace billing is processed through Microsoft. I have therefore been redirected between both parties.

I also found a previous Microsoft for Startups case involving similar unintended Claude/Foundry usage where the customer reported receiving a $1,000 special-exception credit:

https://learn.microsoft.com/en-us/answers/questions/5728641/azure-ai-foundry-presents-third-party-ai-models-as?utm_source=chatgpt.com

Is there a Microsoft for Startups, Marketplace billing, or Foundry escalation team authorized to review a one-time goodwill credit in this situation?

I am specifically looking for the correct escalation path, not asking the Q&A community to access or modify my invoice.