Upvote:3
It's probably not the broker who changed the flight but the airline, which indeed has the right to cancel and/or reschedule flights. However it would seem that, according to the FAQ page from AirTicket24, you can ask for compensation in case of substantial changes:
23. What happens if the airline changes its flights?
The airlines are sometimes forced to modify the itineraries, hours and number of their flights. In this case we will try to inform you for any changes before the date of departure so that you adjust your program to these changes. These changes are usually of minor importance without significant impact on your trip. If significant changes occur related to your flight (for example change in departure time for more than 2 hours or change of departure airport) and you have no alternative that suits you then you can request compensation from the airline, according to the passenger's rights established by the European Union, unless you have been informed on time by the airline.
Hence I would go ahead and contact both your broker, quoting the FAQ, add well as your airline to see what can be arranged.