Seat numbers different to booking. No recourse.

I booked tickets telephonically on 2 March for a show at the KKNK and Liezel at Machine Agency confirmed that that my seats were in row C (C21-C24). When i received the printed tickets from the agent at Checkers my seats now were in row L (L26-L29). On 29 January the same problem occured. My seats moved from row B (B16-B18) to row O (O17-O18). Nobathembu Ngobani at Machine Agency telephonically confirmed the seats in row B, but when I later phoned to complain, I was informed that the tickets cannot be changed after they have been redeemed. The person handling my complaint told me he can do nothing for me. He suggested that I try to swop my tickets at the venue on the day of the show with someone else who might be willing to move from row B to row O.