Cancelling nightmare

I have been trying to cancel for a week now.  As you know, there is no click to cancel on your website which forces you to call to cancel.  When a customer calls to cancel they Xfinity agents won't cancel but instead ask endless questions to attempt to retain you or exhaust you.  A quick google will show thousands of similar complaints of your company dating back years.  This is my documented record of my cancellation.  I have stopped payment and return my modem via UPS.  I would like written confirmation of my cancellation within 48 hours.