Not excusing their lack of support, but at the end of the day you sent a spam/phishing message through their service. What exactly are they supposed to do? If they don't immediately shut down accounts that send these messages, they're going to be in hot water with the cellular carriers. It's by far the lesser of two evils to just shut down accounts that send spam.
No, someone else sent a spam message into Twilio's system, and, rather than dropping it on the floor, Twilio's system then forwarded the spam on to their customer's list, then blamed the customer for it.
Nope, that's not how Twilio works. Yes, someone else sent a spam message, but Twilio did not forward it to "their customer's list" whatever that means. Twilio forwarded it to their customer's application, which was the end of the line for Twilio. At that point, their customer's application sent out that spam message to whoever was configured to receive it. As far as Twilio is concerned, the incoming and outgoing messages have no relation.
Very often people say things that I know are incorrect and actually sound quite stupid, but then I am unable to articulate why. I was very surprised at the number of incorrect negative responses from people to this post, who seemed to grab onto details and then use them to twist reality.
How did you learn to dissect these arguments and then clearly refute them?
Also, I have never heard "distinction without difference" before, but it is a common way that people twist reality. Did you study logical fallacies? Or read a good book on how to deal with them?