My wife and I have IPhone 5s and Verizon wireless just cut our service off without contacting us We had no idea what was going on with this VoLTS stuff. Other people in town had this happen to them also. Verizon should notify customers that their phones are not going to be supported any more in their bill or email. We are looking at Consumer Cellular now.
I am sorry the device stopped working. Verizon did announce the retirement of their CDMA services. Information was sent out via email, and with our bills. You can see more via this link here: https://www.verizon.com/support/knowledge-base-218813/
If you are able to upgrade, I can help you get a new device here. Meet us in a Private Note to look over your account.