How to Fix Chin Implant That's the Wrong Size?

Wasn't my doctor suppose to measure my chin before providing me with a chin implant? My friend recommended her doctor out in Argentina. I worked with him via online (e-mails) for a few months before having surgery. When I arrived to Argentina he already had the chin implant without measuring and now as you can see in the picture it looks so unnatural. Can this be fixed? What is the procedure normally? I was and I am new to this. I have never had surgery before.