@Cshiels0083 you enter the proper 19 digits on the SIM?
is that a brand new sim never been used?
You have problem right after you enter the 19 digits or you have problem with the 2FA?
If your account t was put on Lost/Stolen earlier, you have to resume service before you can do anything else on My Account
@Cshiels0083 - where are you having the issue where 'it wont let you'?
See "How To Change Your SIM Card" at the bottom of this Help Article: https://www.publicmobile.ca/en/on/get-help/articles/sim-swap-fraud