A good technique for dealing with taunts and insults is to use something called "Fogging": This is how it works:

When other people make hurtful remarks, don't argue and try not to become upset. Imagine that you are inside a huge, white fog-bank: the insults are swallowed up by the fog long before they reach you. Nothing touches you.

Reply to taunts with something short and bland: "That's what you think". Then walk away. This might seem strange at first but it does work.