Yes thanks I just checked the Jet2 route map and they do not go to Tunis nor anywhere in North Africa.
Re Jet2 Hols charging a £150pp admin fee to change a holiday I have to say that is a bit steep & mean - I have just had to cancel a huge trip and almost everyone has refunded me in full for all my arrangements - I would defer back to them asking them nicely to consider their loyal customers and that many Operators (Cruise and Tours) are now NOT charging folk to rebook.