Comcast explicitly allows for termination by postal mail in section 9.b.1 or by e-mail in 9.b.2 [0] yet they kept trying to send me to their retention department by phone.

In fact most contracts I've seen allow for termination by writing.

[0] https://wifilogin.xfinity.com/wifiterms.php

Oh wow, didn't realise it was in the contract. That's really on you. Lmao. Don't sign stupid contracts people. Cross that shit out when you sign up or Walk away.