A Norwegian startup faces a $17,600 Claude bill and two vendors pointing at each other, after running Anthropic models through Microsoft Foundry while $21,168 in Azure sponsorship credits expired untouched.

Vegalabs AS said it received $25,060 in cloud credits through Microsoft for Startups and deployed Claude in Foundry in August. The company expected its analysis workloads to draw against the credit balance.

Microsoft’s sponsorship rules exclude that scenario. Anthropic models purchased through Azure Marketplace fall outside the credits, and an account with a card on file gets charged for them.

Microsoft attempted to collect $16,500 from the card Vegalabs had on file, and the invoiced total later reached $17,600 before tax. The sponsorship portal kept showing available credits while Marketplace charges accumulated alongside them.

Microsoft’s deployment documentation states the terms: credit-only sponsored subscriptions don’t work for these models, and an account with a card attached gets charged. Vegalabs deleted the deployment within an hour of spotting the charges. The card issuer declined the payment over suspected fraud, and the remaining $21,168 in sponsorship credits expired Sept. 8.

Vegalabs said it never read the credit exclusions and never configured a budget alert. The company disputes neither the usage nor the documented rule. Its complaint targets the deployment interface, which it says presented a sponsored subscription and a Marketplace purchase as one continuous billing picture.

The refund request then ran into a wall.

Vegalabs sent it to Microsoft support first. The reply said Marketplace transactions process through a billing pipeline tied to the third-party publisher, and that Azure Support cannot waive, refund, or adjust those charges. If Anthropic approves the request, the reply said, Anthropic can initiate the refund authorisation through Microsoft.

Anthropic support said Microsoft did not require its authorisation to process a refund and sent Vegalabs back to Microsoft.

Four of the seven support replies Vegalabs received were AI-generated, including both from Anthropic. Those Anthropic replies described the account as an “Azure Student Sponsorship,” a program name that does not apply to the company.

Reporters asked Microsoft on Oct. 6 for comment and received an acknowledgement plus a request to be told what Anthropic had to say. Microsoft offered nothing further. Anthropic did not respond.

The billing pattern has a trail. A similar case in March involved third-party model charges that sponsorship credits did not cover.