Good morning rita_c
when you book our tour to the Royal Palace you can read in the additional information that the meeting point is outside the Opera metro station, in Plaza de Isabel II. In addition, our guides always give a few minutes of courtesy to allow time for all clients to arrive and you will find our customer service telephone number on your voucher to help you find the guide.
We are sorry you missed the tour, we hope to see you soon and improve your experience with us.
Best regards