In addition we offer you for every rebooked ticket a discount of 50€ on the ticket price. Of course rebooking fees will still not be charged, regardless of which fare was booked. Should the rebooked fare be more expensive due to a change of destination (e.g. rebooking from short-haul to long-haul), change of class of travel or similar, an additional payment may be necessary despite the discount.
The wording here is really confusing, so if you rebook to the same destination and the new fare has now gone up you will not need to pay the fare difference? You only pay the fare difference if you change your destination?