You may have issues with calls if you have:
These steps help identify and resolve the underlying cause. After completing each step, test to see if the issue is fixed. If not, continue to the next step.
Verify airplane mode is turned off.
Verify your HTC Desire® 816 is connected to the Virgin Mobile voice network using My Account.
Be sure your HTC Desire 816 is connected to the Virgin Mobile voice network to make or receive calls.
Verify if coverage is available at your current location.
If your HTC Desire 816 has low signal strength, see if your location is within Virgin Mobile voice coverage on the Virgin Mobile coverage map.
Perform a soft reset.
A soft reset reconnects your HTC Desire 816 to the Virgin Mobile network.
Note: To optimize device performance, be sure your HTC Desire 816 is running the most recent device software. Check for software updates.
If you're still having issues, please contact Virgin Mobile Customer Care.