In my town, there's a perpetual 45-minute line of people at the comcast office. Even though the lady that works there is helpful and friendly, I'd rather talk to an idiot on the phone for 20 minutes than waste an hour or more driving to the office, waiting in line, and dealing with the issue in person.
And yet, the use of that hour is probably among the best than the 20 minutes on the phone. Because you'll try and try, and then you have to return the equipment to the store anyways (or send it back by mail).
And all along the way, they can lose your cancellation, continue to bill you for months afterwards, fail to receive the returned equipment and bill for that, etc.
And sorting it out through the system when you're an ex-customer is 100 times harder because they really will do the hard sell and sign you up again.
The only real option is well, small claims court, which means easily a day of your time, default judgement (what, you think Comcast will show up?) and refund months later.
Or just spending the hour at the store and getting it all done with documentation. (What, you think that record of your phone call will exist? Ha!).
Aren't they obliged to cancel your account if you ask, though? I mean, say you say "i want to close my account", they asked if you're sure, aware of the great deals etc. Say no, again, politely, then firmly "close my account now". What would happen if they continued trying to get you to stay and you stay silent? You aren't obliged to go through their script; you've told them your side of things. Can't you just stop paying them and if there's any come back tell them the date/time of the call, who you spoke to and ask what the problem is? Perhaps there needs to be a mandatory website/service where you just click/say "i'm out of here" and there's no come back on their part?
Yes, they're obliged to cancel when you ask. But they're not obliged to make it easy - they'll just follow their script endlessly. Remember, getting you to hang up in frustration is also a win for them because it's a cancellation that didn't happen.
And if they can make you wait an hour on hold every time, even bigger plus - most people would hang up in frustration.
Mistreat the call center staff and you'll find your cancellation didn't actually take effect, your file number either won't exist, or will contain inaccurate details, etc.
I'm not quite sure why Comcast hasn't emiserated the in-store situation yet; but apparently they haven't, and it's not as though the front-line peons are fucking with you for their pleasure, so if they aren't forced to they generally won't.
Because in-store staff have to do everything - from signing people up, to people wanting to add subscriptions, buy hardware, etc. Cancellations is just a small part of the entire thing that they couldn't be bothered to try to retain you when most of the people in line are just wanting to add a service.
Plus, humans react differently when they're face to face with another human than when they're on the phone, over the internet, etc.