Jawline Botox Gone Wrong? (photo)

It sounds like your provider massaged and the product diffused to other muscles in your face that would normally allow you to smile. Instead of just going in to your masseters as expected, it's where it shouldn't be now. You'll have to wait out the treatment (wearing off).

Your Botox not only affected your masseter muscles, but also the muscle on your left side that helps you smile.  The massaging probably spread the Botox into this area.  You will need to wait it out for a few months until the effect fades.