Day 96 of a 21 day wait!

My mother has been out of work since August. Her completed papers were filled out by 29 July. She was told 21 days. We are on day 96. She constantly gets asked for the same documents that she sent out the first time round. This is a delaying tactic and it's getting ridiculous. This is truly unacceptable. Her file keeps getting passed around without actually being tended to. 96 days when she was told 21! Seriously. Fix it!