Connect an account previously created

Connect an account previously created

I created an account (A) in my business domain name earlier and didn't connect that to the website. Later I used another previously created account (B) to create and link that same domain. 

Now I am unable to connect account A with domain which is already connected on mail via account B. 

I tried to delete Account A, but there is no option as the mail isn't connected and neither is any page. 

Please help urgently.