That's never worked for me with D*. They've tried to charge me for not returning my owned equipment on many occasions over the years. It's taken many hours over the phone to straighten out their messes. I don't know if Dish purposely tries to cheat you like D*, but I'm not taking any chances. D* will lie to you on the phone and say you owe nothing and then surprise you with thousands in bogus ETF's and non-return fees. Best of luck to you when you cancel D*. Watch your bill very carefully.
I was anticipating a bunch of bogus charges so I changed my credit card number. They don't have it any more. And the contract was signed by someone else probably 7 years ago.
Anybody that has your credit card number can start charging things arbitrarily and the only way you can stop them is to change CC numbers. I use Paypal whenever possible because you have to approve every charge.