Calling USA while roaming in EU on UK plan

Hi, I'm currently in Poland roaming on a UK plan with 100 international minutes left and trying to make a call to the USA but it is not allowing me, it says I not allowed however it let me while I was in the UK, what is wrong, I'm meant to be able to do everything I can at home according to the Lebara blurb!?

If you have a look at the rates page CharlieS1 it states that international minutes can only be used to call other EU countries and India when roaming.