New customer

I have inserted new idmobile sim card into my samsung s5.and transferred from 3 to idmobile via a pac code as i was told by idmobile i need a pac code from 3...this has all been done and activated.but even though i have network bars i cant make or recive calls,texts or data.if i try to make a call it says you dont have any allowance.if someone tries to call me it goes to voicemail.text msgs fail.ihave tried all the usual turning the phone off and on.reinserting sim.but no joy.my phone is unlocked.have tried to go to networks and search manually but i only get the usual 3,EE,vodafone etc but not id4g network....any ideas? As idmobile cant seem to work out whats happening...thanks all.