You basically have 2 options here:
1) Do a Factory Data Reset. (Look in Settings/Privacy/). That should give you back network service, but you'll loose all your downloaded apps, and any contacts or emails that are not synched to the cloud will go bye-bye too. Still, it is a sure-fire method to get everthing back up and running.
2) Take the phone into a Telus store and ask them to fix it. The techs there should be able to figure out why the phone can't make calls.