You say "no internet" but then you also say "[no] network signal".
Which is it?
Did anything change on your phone recently?
E.g.phone software update, reconfiguration of settings etc.?
What make and model of phone is it?
Have you tried switching off, taking the SIM out, gently cleaning it, reinserting it, switching on and seeing if that makes any difference?
If not then you will probably need to contact 48 support (see the link in my signature below) and maybe try a replacement SIM in case your current SIM has failed for some reason (I don't know why but this seems to happen from time to time to some users and their SIMs).
Hope this helps.
