Perhaps I should clarify exactly what happened.
We (family of 6) were booked to travel Dublin-Stansted on Thursday last , but with Dublin Airport snowbound and having rebooked three times for Thursday evening we eventually gave in to the elements and got Ryanair to rebook us from Belfast , which was fully operational , for first flight on Friday morning.
My problem now was that my car would be in the car park at Belfast City Airport so I requested them to reroute our return to there , which they kindly did.
On check-in at Belfast we were directed to the kiosks which , I have to say were great , I did not have to pay for check-in on the outbound flight , so assumed that the return would be the same but , alas , I was asked to pay.
When I queried this at Stansted this morning i was told that the kiosks were not "online check-in" and therefore the charge stands.