Authorized Retail User

Phone lines cannot be removed in store at all. By anyone.

If anyone needs to cancel a phone line you must call AT&T.

Authorized users can make purchases, change plans, add new lines. 

Primary and secondary users and Authorized users can cancel service on tablets or watches and dedicated hotspot devices only.  

@SHAKA07151978  If you want to do business in a store, you might be better off looking around for an AT&T Corporates Store instead of an Authorized AT&T Retail Store. You likely to have less problems, or no problems at all with a Corp Store.