Text Messages

my phone will not send of recieve text messages and all of my pictures and emails deleted on their own. i keep getting a message on my phone that says to delete items from phone memory and have called tec support numerous times. they cant seem to help me with this problem. i have also taken my phone back to factory settings and this hasnt worked. this phone is not damaged from dropping it and has not been water damaged.  Can you PLEASE help me or replace it. it is an e71 and was purchased in July from Walmart in Chillicothe, Ohio.