Billing Issue: Duplicate $20 Charge After Plan Downgrade

To Vercel,
We have already paid an invoice of $20. However, one of our team members accidentally downgraded to a lower plan. Despite that, the $20 has already been charged from our account, and now we are being asked to pay another $20 invoice.
We sent an email a week ago but have not received any response yet. Please review our account and resolve this issue as soon as possible.
Thank you for your cooperation.

Thank you for your patience! Our billing team will get back to you.