Any punter getting into a back and forth of text ping pong risks being considered a timewaster also. All you have to do is ask if she's available at the date and time you want, confirm the services you want if any extras are involved and the postcode for the location of meet. Takes 1 short opening message to communicate that. If call-taker is evasive, erratic and/or has limited English that can drag things out. If c-t is responsive then they're keen to make a sale but if you stretch it out and start talking about something other than the booking you're the one wasting time. Consider all the calls they receive and the whackos involved, you want to meet an SP and have a chat that's fine once you've paid for their time.
This "alert" from you after just 3 messages speaks to your presumptuousness. If it was the SP answering she may've had a punter arrive, if just a maid they may've had another phone to answer a call on, etc. There's no obligation for either to pick up on comms if they get busy or are dealing with people who are more efficient in confirming a booking.
Just because you're frustrated because you couldn't make a booking doesn't mean the SP isn't busy taking clients, especially if she's young and attractive. You aren't entitled to a booking.