Telus store would not help with PM account issue , you can only buy the sim card there and do it yourself. and you are NOT porting your number, you just try to update your sim card to your existing account (porting means from another provider)
Once you got the sim card, go to My Account to request Change Sim card
(If you are unable to login as you don't have a phone to receive the 2FA code: On the screen it is expecting you to enter the code, click Didn't get the code? or Resend code and then choose Send email)
After you logged in, unsuspend first if you have suspended your service earlier.
Then go to Profile page, click on the Pencil besides the sim card number, follow the steps to enter the new sim card number and complete the change sim card request
(or direct link: https://myaccount.publicmobile.ca/en/account/profile/change-sim-number )
After the sim card is updated, wait 5 mins, then reboot your phone and it should be good
