I'm sorry to hear about the issue you're facing. Based on the information provided in the extracts, it seems that you might need to reach out to OpenAI's support team directly for assistance with this specific issue.
However, it's worth noting that when you cancel a ChatGPT Teams plan, it's important to ensure that you have not deleted your Personal Plus account. As per the forum post (https://community.openai.com/t/619497), cancelling your Personal Plus account before migrating it to a Team account can result in the loss of your chat history and GPTs.
If you have not deleted your Personal Plus account, you might be able to switch back to it. According to the help article (https://help.openai.com/en/articles/8801890-can-i-migrate-or-merge-my-chatgpt-free-or-plus-workspace-over-to-my-chatgpt-team-workspace), you can switch between workspaces if you have both a Personal and a Team workspace.
If you're still having trouble, I recommend reaching out to OpenAI's support team directly for further assistance. They should be able to help you reactivate your workspace or guide you on how to switch back to ChatGPT Plus.
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: