i have a samsung S5 neo and its constantly restarting

[AC Question]

Since i upgraded my phone in April its constantly restarting ive tried everything that ive been told to try and its still doing it and its getting very annoying now its a contract phone with virgin so please does anyone have any idea's because i dont fancy having to go and buy a new phone as this is still only 4 months old and still under warrenty. PLEASE PLEASE CAN SOMEONE HELP BEFORE I THROW MY PHONE AT THE WALL.