I recently bought a £35 SIM card from Three at the airport, which was supposed to provide 150GB of data for my month-long trip in Europe. However, once I left the UK, I found out that I only had access to 12GB of data when roaming, which was not disclosed to me at the time of purchase. This left me with insufficient data for most of my trip, causing significant inconvenience. When I contacted Three to complain, they said they could only contact the store that sold me the SIM and refused to offer any credits or partial refunds. This lack of transparency and poor customer service is a scam.