I’ve got permissions to do account assignment within my wing, I’ve never come across a situation where I can’t assign someone a role 
Sounds like you have been transferred to Region.
So you are no longer part of the wing so your wing bader Officer can’t allocate you.
You can ask the Region bader Officer to do so though
What @themajor said.
When you are transferred to a unit thats outside the wing you are auto unassigned from accounts in that wing.