I’m assuming you are referring to this topic?
Next time, if you have a question related to a topic, please link to the topic yourself. It gives us a bit more context than “some people in some topic with some issue told me to do something”. If we know what you know, that helps us help you.
It seems like something went wrong with the domain administration of your account, where the domain may have been deleted, but not completely.
I can check this for you, but you have already deactivated the account, which prevents me from helping you. If you want me to help you, please reactivate the account and please try deleting the domain from it again.
Alternatively, you can wait for the account to be fully deleted, but then it may take 60 days before you can use the domain again.