What causes Cell Phones to freeze and eventually result in erasing all of your phone numbers, contacts?

It has been happening with my cell phone lately, I have the LG Octane, and i've only had it since last December, so like 6 months now, and for a couple of days now, probably a week it has been starting to freeze up, whenever I press the up button on the "OK" pad to go to the Verizon services Menu, I use it to check ESPN the scores for games, and for movie-times, schedules, the Bing to search the Internet, it freezes, whenever I press the "Up" button, it causes my cell phone to freeze, and I notice I am unable to delete text messages as well too, and today it finally crossed the line, in which my Cell Phone erased, deleted all of my phone numbers, contacts. Has this ever happend to anybody before?