Please provide a screenshot of the Wall tab and its missing button. Please navigate to group edit and check the wall post permission to ensure the user you're attempting to test with can even post. CB moderator, category owner, and group owner are exempt from this parameter of course and can always post.
Please do not PM credentials that were not asked for. We do not do install review at users request, but only when we feel the debug process has been exhausted. Support does not include direct contact; that is a paid service unless we determine the issue to be a bug.