We have about 20 PSTN-enabled meeting rooms. We're also running Skype CCE. We're not able to change the PSTN numbers on any of them with neither the Set-CsMeetinRoom -LineUri nor Set-CsUser -LineUri or -OnPremLineUri. It always results in an error telling me that the "This parameter is restricted within Remote tenant powershell."
I have to keep opening tickets with the Office 365 support and go through all the diagnostic steps over and over again, despite telling them we did this already. I'm on the verge on throwing it all out and get a third party solution for my telephony!
Please let me know how to change PSTN numbers myself, thank you.