How to turn off iMessage on iPhone 4?

Everytime I send A message to someone on my iPhone I get a response from them but on my iPod… And I don't like it how do I turn it off I tried going to general and iMessage turned it off but still it's messed up or sometimes when people send messages to my phone I receive them on my iPod and not phone? Someone tell me how to fix this?

Go to settings then messaing and it will say imessage then say off.