I know it's scary when a bill is unexpectedly high. Thank you for your patience while the support team works through other requests that were opened earlier.
From what I'm able to see, there was an original invoice for the first seat on your v0 team and a prorated invoice for the second seat when another team member was added. The billing specialists will be able to see more details than I can, so it's best to wait for their help. Billing issues and refund requests are typically handled quickly. I expect you will hear back from the team very soon.