Rolling Plan in Channel Island

[Ri2]

I live in Guernsey Channel Islands and I used to have a pay as you go account for 2 years and only use my O2 sim whenever I visit UK but switched to Rolling Plan just yesterday. 
However, my mobile data is not working when I went back to Guernsey, I’ve restarted my phone, waited and turned on my Roaming but it’s not working at all. My friends have been using O2 and it works for them. Please help!

[Enlli · Accepted solution]

How much credit do you have? The rolling plan payment will only cover you for calls / data  in the UK

You need to put credit on to cover  use in Guernsey