jet2 on line booking

Has anyone else booked seats with Jet2 for the return trip from Dalaman and paid £8 only to find that there is no on line checking in at Dalaman and are not given the seats requested? They did this to me last year and I eventually got a refund. I did it again this year thinking they must have got on line checking in only to find that when you print the boarding passes it says there is no on line checking on the return section of the boarding pass.It seems they are charging people for the return trip even though they know you cannot book seats for the return journey