So I'm new to ID. I'm on tour in Europe for 3 weeks and I used up my 30gb roaming allowance. So I bought a £30 Add On, but still couldn't get any internet. I increased my cap and it's working but I'm being charged now.
I read that the add ons were useable when Roaming (Netherlands), but I'm not sure why I'm being charged for data on top of that.