Help: ZTE ZMax Pro volume down button not working!

A

AC Question

I don't know what to do the other day my phone turned off and would not start. I took it in to get it checked the person said oh just hard restart it. So we did and she said if it happens again bring it back we can switch for another phone like yours. A week later it did it again turned off so I just reset it.I have had my zte zmax pro for about 4 months now. I had to take my original in 3 months after I had it because It constantly kept getting hot,glitching,sending lots of text messages when I only sent one, and it would shut off on me I bought it brand new. So now I have a second one because maybe it was just the phone. Well this one is getting hot too, still sending multiple messages to people, and the volume down button is not working. Any suggestions for me I don't want to have to go through T-Mobile and get the same phone again.