30gb for £15

[gp2]

I have an offer to get 30gb for £15 - so have topped up £15 but only have 15gb instead of 30gb, why is this?

[pgn]

Have you followed the instructions to avail of the offer, @gp2?

All here, at the link below: 

https://www.o2.co.uk/shop/sim-cards/pay-as-you-go