From what you've written it's not fully ported over yet, just needs more time.
I trade in Gold Mobile numbers, sometimes you can get dual service on the old sim and on the new sim. It can take time for your number to fully move over. It is best to switch the "new sim phone" off and on every couple of hours for the services to update and refresh.
If after a couple of days it is still doing the same then you may need to escalate it to technical support.
