They do that sometimes.  They are not very reliable.  The girls are ok looking, nothing great.  Some of the girls provide a good srvice but you have to check their reviews before you mak an appt.

Sometimes they take a night off.  If after a few calls no one has picked up they aren't operating that night.  Wait a day and try again.

I have used them a couple of times with hit and miss results.  Typically one cup with extra cups offered for additional gratuity.  The plus side is that they don't bait and switch.  the pictures on the site are real.  Check for reviews though.  They should steer you straight.