Hi nanpur
From your post, I am assuming we are talking about NS ESA.
When your husband was informed that he was not eligible to claim ESA was this due to failing the WCA or not enough NI contributions. If it was because your husband failed WCA then he needs to contact DWP and ask for a copy of the assessors report called UC 85.
I would advise you to seek help from your local Welfare Rights Organisation; you can find your local Welfare Rights Organisation to help you with advice by clicking on the link below and putting in your post code, it will then come up with a MAP with a list of agencies.
advicelocal.uk Gary