Thanks for your post, and I'm sorry to hear about your S4!
Sounds like there may be a problem with your handset itself. All of our phones (new and refurbished) come with the same one-year warranty,
Please contact us at Support and we can go over some troubleshooting, as well as your warranty options. You can reach us at 1-888-250-5255, Mon-Fri 9am-10pm, and Sat-Sun 9am-5pm Eastern Standard Time. You can also use the link below to schedule a callback time more convenient for you.