Me_too
I'm afraid the Equality Act, as important as it is, rarely offers a solution to the issues that a claimant might have in regard to benefits.
So if a complaint to ATOS and the DWP fails then you only further option is to make a formal complaint under the Act, you'll need to get face to face advice about doing this. However, the complaint is a separate issue to the benefit process and is very unlikely to result in a decision before that benefit process comes to a conclusion.
In all honesty you would be better off contacting your MP about the situation.
Contacting your MP Gordon