Please, please try this group before you contact any sorority's alumnae chapters directly. Let them know that you tried to contact the LA APH and have not had a response.
http://www.sccap.info/
As has been stated, alumnae chapters can vary GREATLY from group to group and chapter to chapter, and the last thing you want to do is lobby a group for recs who for one reason or the other does not concern themselves with that.