Changing 365 User Name causes loss of mailbox, can't find it to connect to new user name

Question

• I could not find a procedure to do the change needed properly, It doesn't seem to exist, or not easily found, so I created a new user, and then applied the old mailbox to that user - it would not do it
• I then defined the mailbox for shared use 
• Then deleted the original user
• assigned the mailbox name to the new user, and it set up a blank mailbox
• Supposedly the now "GHOST" mailbox is available for 30 days, but it is not on the list of disconnected mailboxes.
• I am not the savvy programmer using the commands I see in some recommendations that don't match the exact problem, none of which explain WHERE to enter the commands supposedly helpful to find it under, I assume Exchange Server of 365.
• I think this is a bug in 365, the mailbox is for [e-mail]
• HELP!!

Answer 1

forum migrated to mentioned below link please use this

https://docs.microsoft.com/en-us/answers/index.html

 hope answer the question if issue resolve please accept answer