Question about unavailable Twit and Ig usernames

[Remote]

Does anyone know a solution to register usernames on Twit or Ig that have not been taken but still say "This username is use" or something like that. The usernames have not been suspended, they don't violate the rules, and they have been deactivated for more than a month. For instance like these usernames: @  Root on Twitter and @ r on Ig. Does anyone know how to register usernames like these or why they can not be registered?

 

[Gym]

I always hear "contact support/staff", etc. But have never tried it.

 

[Ellis]

I always hear "contact support/staff", etc. But have never tried it.

Is there a individual contact for twitter as all the contacts I see after the message has been sent says something along the lines that they can't reply to individual problems but will use the info as a whole to help out?

 

[Brian]

Someone probably tried to swap "Root" on twitter. There's a rule that you can't swap anything 4 chars or under. My friend was giving me his 4 Letter twitter and he tried swapping it to me and it got deleted.