This link should work for you
http://www.turismozaahj.co.cl/frecuencias_es.htm
I should have given you the English link,
http://www.turismozaahj.co.cl/portada_eng.htm
OK now I am a bit confused, in your first post you ask about getting from Chile to El Calafate, but then you state that this bus company cannot pick up passengers in Argentina...I don't see why that is an issue since Cerro Castillo is in Chile...Am I missing something?
suerte
SAM