As a kid, I was bullied -- for my looks and my weight and generally because I didn't fit in. I just ignored the bullies. The more a person whines and cries about being bullied, the more he or she is bullied.
Now I'm an old bag who didn't have internet, smartphones and what not growing up, so maybe it was easier for me to ignore the bullies. One thing I would do if my child was bullied is to ditch the smartphone and forbid the use of social media. Makes it a bit harder to be bullied if the means are not available. The kids really don't need these things. They can call or visit friends in person and if they need to call in an emergency, a basic phone will do.