You wont get a free gamertag change.Your gt doesn't violate the code of conduct.
Block comms with anyone making fun or set up communications to friends only.
If you want to change your gamertag then you will have to pay like everyone else.
Having a 3 in your gamertag in place of a letter is so L3git. 4 reals... :D
Don't listen to them your names is okay. Haters gonna hate, just block communications with the fools.
You can edit your profile and change your gamertag but it costs $10. If you really dislike it that much you might be better off just creating a new account, but personally I wouldn't worry about what others say.