Same issue I bought the family tickets and when I went back to book some extra ticklets I was told that they had sold our seats twice. It took a while to sort it out but they had to ring the people up who thought they had bought our seats (halfway up on the halfway line)and tell them they didn't have a ticket after all.
Interesting phone call
Bet when we get to the game a load of seats have been sold twice, I hope the stewards have been warned.
I got the feeling that I wasn't the first person this had happened to.
Oh dear