From my reading, if you do the csr roulette and make a lot of moves getting discounts, or doing the "want to cancel" boogie to get cheap stuff, they eventually flag you and make you an unwanted customer, which means you get full price and no discounts. Also read that this stuff can stick with you years after the fact.
Now Im talking about the person that calls in to cancel a premium they dont want and then gets 50% off for 6 months if they opt to keep it. End of the day, once you have abused the "discount" process you get a flag and it does not come off with time was my understanding.