Haven't had to cancel yet, but haven't had any problems with them except one:
Bill went up almost $40 - unpleasant surprise - and when I called, the gal there said it was because I'd come off the introductory rate.
I don't recall anything about an introductory rate when I changed from DirectTV to Dish, but whatever.
Since n=both are now owned by the same parent (AT&T, IIRC), it's more like they matched DirectTV's price.
Dish has been separate from ATT for years now.
Once ATT started Uverse they split from Dish, but that only serviced people who had their ATT DSL.
They bought/merged with Direct TV and that ended them have DSL ever being available by us (rural).
The phone techs has said the had been supposed to have DSL available to us in a matter of months, but the Direct TV merger ended that.
We have a line of sight type of internet, a dish on our roof to a tower about 4 miles away.
If we didn't live on top of a tall hill (highest point in the area) it wouldn't be available.
IMO, Satellite TV and internet sucks.
It's too reliant on clear cloudless weather, any type of precipitation and you lose the signal.
I've had Dish since 2006.
They keep looking for new ways to raise the bill also.
Charging for local channels is one of them they added to the bill.
I added an over the air antennae recently and I should be dropping the local channels off my account with them.
As far as cancelling an account, friends have had problem with both Dish and Direct TV on dealing with that.
I think that they all suck when it come to customer service.