You may need to try that tip many times before it works. Switching airplane mode on and then off and trying the roaming profile reconfiguration may help to catch it just as it gets a brief connection to a local network allowing the reconfiguration to be effected.
If that's not the problem then post back with more info about what is wrong.
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.