If you've taken the same 3 AS levels on to A2 (eg you've done the three sciences at AS then A2) then they only count once - you'd have 280 UCAS points.
If you've done another AS which you dropped after the first year, then that counts, but for less points (A=60, B=50, C=40, D=30 etc).
Hope that helps
Has the woman phoned back yet? I think you should phone again, in case she's forgotten!
Actually, can you still access that page? Cos if you can't, it suggests that it was a page you weren't meant to be able to see!