Hi Alake,
Thanks for your post and welcome to the forums. It's great having you on board with us in the Community.
I'm sorry to hear you're having an issue with making calls since your number switched over.
Usually it can take up to 24 hours for everything to transfer over so give it today to complete. If after the 24 hours you are still having an issue, reboot the device and try again. If you are still having an issue at that point, pop back and let us know so we can help you further.
Many thanks,