Severe muscle atrophy after Botox injections. What can I expect?

I had severe muscle spasm in the right side of my Semisplenius capitis and Splentis capitis muscles. 7 months ago they have been injected with a high dose (approx 400 units) of Allergan Botox. I have now severe muscle atrophy in around the injection sides in these muscles. They are painful, thin, lumpy, inflamed and burn almost all day long. I'm doing neck strengthening exercises for many months, to reactivate/regain muscle mass, but no result. What can I expect and do about my situation?