on my zte speed and warpthe problem is it cannot decipher between LTE and 3G go to your network settings and there will be two choices LTE/coma or CDMA all by itself click on the CDMA it will now be on 3G can your phone will workof course you won't have 4G but your phone will work the difference between 3G and 4G is internet speed my phone works perfect now hope this helps

Hi Amy! When this kind of thing happens, usually it's a setting that can be changed only by your carrier. Basically, your phone number has a setting where you can specify how many times it rings before a call goes to voicemail. Try to get in touch with them to find out more about this, and fix it so that you are able to pick up calls without problems. We hope you find this answer useful!