What am I entitled to if the seat or the type of cabin indicated on the ticket is not provided?

You are entitled:

(a) to cancel voyage and be reimbursed with the fare  (passenger and vehicle) and compensation increased by 100% of the fare passenger or,

(b) to travel in lower class and receive the price difference between the passenger fare class seat increased by 100% or

(c) After your request and the company’s agreement, you may travel in a higher class paying the difference in fare price reduced by 50%.  This fare price difference is not paid if the company itself, without your request, provides you a higher class ticket.