booked etihad and flew on a jet airways aircraft!

I specifically requested to fly with etihad because of their \good"seating. I could have chosen Emirates but chose Etihad due to connections to India. I was told that the aircraft would be Etihad and the e-ticket had an Etihad flight number \""EY\"". When I checked in at Johannesburg airport I found out that the actual carrier was Jet Airways"