Your phone seems to be incompatible with Fido network. What is your phone model. And do you have selected Fido in carrier settings?
I hope this will solve your problem.
Have a nice day, It's been a pleasure to assist you today.
Welcome to the community!
Sorry to hear you're having issues making/receiving calls with your phone. What phone are you using? Was it purchased from Fido? If not, have you verified it is compatible with the networks? You can view the compatible bands/frequencies here. You should note that even with compatible bands/frequencies, coverage would depend on corresponding bands/frequencies used at your surrounding cellular towers. You can get an idea of your area towers here.
Are you able to use other services (ie send/receive text messages or use data)?
Hope this helps 😀