Founders Hub billing issue - stuck between Microsoft and ISV with no resolution path

Hi everyone,

I'm reaching out to the community because I've hit a wall with standard support channels and hoping someone from the Founders Hub team or other founders who've faced similar issues can help.

QUICK SUMMARY

I'm a Founders Hub participant who got charged ~€1,000 for using Claude (Anthropic) models through Azure AI Foundry. I assumed these were covered by my $25k Sponsorship credits since:

• I used ai.azure.com (not a separate marketplace)

• There was no clear warning about separate billing

• There's no way to monitor Marketplace spending in Founders Hub

THE PROBLEM:

I'm stuck in a loop:

• Microsoft says "contact the ISV for refund approval"

• Anthropic says "billing is handled by Microsoft, not us"

• The "Support" link Microsoft points to redirects back to Microsoft Support

I've sent detailed emails explaining this circular situation. Support keeps responding with the same copy-paste policy text, ignoring my request for escalation.

MY ASK

1. Is there a dedicated support channel for Founders Hub billing issues?

2. Has anyone from the Founders Hub team dealt with similar Marketplace confusion before?

3. Any founders here who successfully resolved unexpected Marketplace charges?

I'm not trying to get something for free - I already paid the first invoice (€460). I just want help with the second invoice that surprised me a month later.

The Founders Hub program has been great otherwise, but this experience has been really frustrating. Any pointers would be hugely appreciated.

Thanks!

Bartek