Just a short update regarding the taxes, I got on the phone again with the ICC (after I was unable to reach the refunds department), at first the ICC seemed not to understand what I was talking about "the taxes are calculated by the systems", but after I explained myself about three times I was put on hold, after about five minutes I was asked if they could call me back. I risked it and actually got a call back about twenty later, my taxes were indeed miscalculated, now they are corrected down to 470 GBP instead of 525 GBP. I'm just wondering what is going to happen now, according to the ICC the trip won't have to be re-ticketed, I'll just receive a refund of the tax difference.