Good afternoon Paul and welcome to the Events Calendar Support forum!
Thank you for reaching out to us.
We are sorry to hear about the upgrade process not being smooth for you.
I would love to help you with this topic.
The simplest way to handle this would be to ask for a refund of the renewal transaction.
In order to do that, you just need to follow the procedure described here.
Make sure you reference this thread in the form to explain, that you are keeping the business license and the renewal of the personal license was just a glitch in the process.
The reason why that would be the best approach is because as soon as you upgraded to a business license, the personal license ceased to exist. It was converted into a business license (with the same key).
Let me know if that helps.
Have a great day!
Geoff B.