The one who blocked you is a write off, forget him. You might message the guy who saw your last message one more time without seeming desperate. If no reply, just move on .
One has no idea what is going on in the minds and lived of other people. You may not be their highest priority at a given moment. Generally the professionals will get back to you to confirm or cancel, but not always.
I had this happen to me in Palm Springs with a well regarded escort from LA who was coming to PS for the weekend. We had confirmed twice. In the morning of our evening appointment I found his ad had changed form PS to LA. I messaged him and finally got a reply that afternoon that he had missed his flight and wasn't coming. It would have been nice for him to let me know. So it goes.