What country are you in? Also what make and model of phone are you using?
Remember that EU roaming only works on Guido membership and not on any other membership. Roaming calls and texts (but not data) in the rest of Europe, North America and Oceania (Australia/New Zealand) work on any membership but you need cash credit on your account to pay for outgoing calls and texts and incoming calls. Roaming does not work at all in any other region/country.
Hope this helps.
I am not a 48 employee so if you need to contact 48 support then use option 3 or the chat facility here.