On the topic of "auto-pay" in general: it's a trust relationship. I trust my cell phone provider. (they're very service oriented)
I do NOT, however, trust my electrical utility company. They are notorious for being officious, bureaucratic and error prone.
While they haven't screwed up a bill yet, I don't let them auto-charge me because it's plausible they will misread a meter and bill me for the electricity consumption of a small aircraft carrier, completely oblivious of the fact that the wires leading to my house would
melt instantly if I attempted to draw that much energy.
This has happened to some customers, despite the fact that the laws of physics didn't support the level of consumption the utility company was claiming.
So, they go on manual pay and I audit them every month. They can take it up with a arbitrator or judge if they pull any shenanigans.
Comcast? Sounds like a company nobody should trust.
I only trust my bank to a point and set my bills to auto-debit the
day after payday because of
payment re-ordering scams banks are notorious for.