Delay on reconsideration decision

Dear Friends,
My wife's settlement application was refused on 17 September 2018. This is because I work for my brother they said I had to provide the documents of the business as they classified it as specified limited company. They have made a mistake because my brother is sole trader not a Ltd company and the documents they said were required cannot be provided as its not Ltd company. I have lodged a pre action protocol on 18th September but they havent responded than I have got the local mp involved and they finally responded on the 9th November 2018 and agreed to reconsider the decision 3 months. The 3 months is gone and I have contacted them they have finally responded but instead of giving decision they saying we cannot give you time scale but we are working on the case we will be in touch with you as soon as possible. Did anyone have the same problem what would you recommend me to do as it has already been 5 months