I just got a reply!
A few other customers are in the same boat. We have contacted the venue and they have said they will let you into the venue on the night but you will have to enter via the box office entrance,
I paid €155 for 2, do you know if that's the price for normal GAs? Cause then I imagine the student ones are cheaper, which indicates that it must be some error.
Plus it says "full price standing ticket" in my order.