The Smart Benefit is just a billing add-on to help reduce the cost of roaming.
Did you text ROAMING to 150 before leaving the UK? That enables the roaming facility which then allows your phone to connect to foreign networks. Your symptoms suggest you don't have a connection to any Italian networks.
If roaming isn't active, you will need to contact EE CS from another phone or potentially a web-calling app, to do so.
