You can challenge the decision at an independent tribunal.
The tribunal will listen to your arguments, look at the evidence provided and tell you their decision.
There are strict time limits for taking cases to a tribunal. You should normally get your appeal in within 1 month of the date you received the mandatory reconsideration notice. In special circumstances this can be extended to 13 months (for example, if you were in hospital, needed an interpreter, or you live alone and had difficulty understanding the letters). Make sure you explain any reasons for applying late.
The easiest way for you to appeal is to complete a SSCS1 form.
Get advice straight away if you want to appeal. A benefits adviser might be able to help you fill in the form. Contact Citizens Advice or use the advicelocal guide to search for an adviser near you.
For more advice on how to take your case to a tribunal click here.