Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
If you redeemed your Microsoft product renewal key on the wrong Microsoft account, the first step is to verify which account the subscription was applied to by signing in to your Microsoft account and checking your Services & Subscriptions page. If the renewal appears under the wrong account and has not been used as intended, contact Microsoft Support as soon as possible and provide your product key, proof of purchase, and the email addresses for both the incorrect and correct Microsoft accounts. In some cases, Microsoft may be able to assist with transferring or resolving the subscription, depending on its status and eligibility. Avoid redeeming the same key again or purchasing another subscription until the issue has been reviewed.
I hope Microsoft Support is able to help recover your subscription and apply it to the correct account.