Why removed user is added to database again ?

I am creating a custom plugin.using a separate table to save the data, there is a page that displaying all users and link to delete the user, now deleting the user deletes the user from database, but when I reload the page, I am getting the user added back just with a new id.

this gist has the code,
https://gist.github.com/PrafullaKumarSahu/5473b723e26b45b366f0354d654e6173

if I need to post or add more details, please let me know.