iPhone, Unable to Activate

Hi so I tried to update my iPhone XS Max to the latest IOS because my phone would not make calls or texts without the update. After the update my phone still wouldn't make calls or texts. So I factory reset my phone and it showed up with "Unable to Activate." So then I plugged it into my Mac book that updated to the latest Software Update and I put my phone onto restore mode and I updated and restored my phone, and it still would not activate. What should I do?