[BUG] Account downgraded due to billing error

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Summary

Upgrading from Max 5x to Max 20x resulted in a full $200 charge instead of the prorated difference, and my account was subsequently downgraded to the free plan.

Actual Behavior

• Full $200 charged with no proration applied
• Account downgraded to free plan after the billing error
• Support confirmed refund but stated it will take 5 days

Impact

• Unable to use Claude Code for work during this period
• No funds available to repurchase the plan while waiting for refund
• This is directly blocking my work right now

What Should Happen?

• Prorated charge of ~$100 (the difference) for the remaining billing period
• Account remains on a paid Max plan

Request

Please investigate and restore the Max plan (at minimum Max 5x) to affected accounts immediately while refunds are being processed.

Error Messages/Logs

Steps to Reproduce

1. Have an active Max 5x subscription ($100/month)
2. Go to Settings → Billing
3. Select "Upgrade" to Max 20x ($200/month)
4. Confirm upgrade

Claude Model

Other

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.172

Platform

Other

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Additional Context

• Support Conversation ID: 215474648762539
• This appears to be the same pattern as issues #10832, #43118, #50710
• Refund was confirmed but 5-day wait is not acceptable given the error was on Anthropic's end