First off, if you haven't already I would post in the Hughes Community:
»community.myhughesnet.co ··· t/topics
Doing so will create a record of your issue with the forum Mods. They are located in Germantown and are associated with the Hughes ECC department.
As such they can cut through the red tape.
On actual cancelations ... Hughes has the annoying habit of not canceling immediately but waits until the end of a current billing cycle before sending out "Return Kits" ... and then sometimes they need a push from the forum Mods to get it right.
When you do get the kit, save the tracking number ... returns HAVE been known to get "lost" in the warehouse.