To better answer the question in the thread title:
I deactivated a leased Hopper last month. It took Dish two weeks just to send me an email to remind me that the Hopper needed to be returned, stating that they would send me another email when the return kit actually shipped. A few days after that, I got the second email. A couple of days after that, the return box arrived. So, the answer is: almost three weeks.
For those who are keeping Dish service, and simply need to return a leased receiver, my advice would be to simply reactivate the receiver if you haven't received the return kit within thirty days. This way, you can avoid the fee for not returning the receiver. Then, you can deactivate the receiver again, and start the process all over again.
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