Hi. I recently switched to a new phone and was having a similar problem after trying to activate it. Everything seemed to transfer over just fine, but for some reason I couldn’t make or receive texts or calls. I found this forum while looking for a solution, and even though it’s kind of old, I just thought I’d share what eventually worked for me in case it helps anyone else. After trying a few things on my own and having no success, I called customer support and what finally worked is when she asked me to reset my network settings. After I did that, texting and calling started working just fine. I reconnected to my Wi-Fi network and thankfully it’s all working good now.
I’m not sure why my network was interfering with making calls and texts at first, but if this sounds like your issue try going to Settings—> About Phone then go all the way down to where it says “Reset”. From there go to Reset Network Settings. Hit the Reset Settings button and confirm. Try making a text or call. If it works, all you have to do is reconnect to your Wi-Fi and you’re all good! Thanks and hope this helps!