I'm not sure I'd categorize escorts in general as being "over us" based on an experience with three escorts in San Diego. In fact, I am quite sure I would not.
That being said, I typically email or text on first contact. That would not help in the case of the guy you emailed, as he did not reply after you answered his reply email, but it could in the case of the two guys you called. They do share some of the responsibility as all mobile plans include voice mail. Don't want to talk? Let the call go to voice mail.