The Jobcentre was told to apologise after mishandling a claim a from a disabled man who was left without money for several months.
Andrew Lamont, of Wakefield Road, Earlsheaton, was not informed that his benefits had been stopped and Jobcentre Plus (JCP) incorrectly said he did not attend an assessment.
Mr Lamont, 50, said that the delays and cuts to his benefits affected his health and left him dependent on his elderly mother.
He said: “If this is how they are treating people then god help us as a society.”
Mr Lamont, who has suffered from severe arthritis and other problems with his knees, was helped with his claim by former Dewsbury councillor Glyn Powell.
Dr Powell said: “Andy would have been destitute if his mother, a woman of 80 years, had not been there.
“If I was Iain Duncan Smith I would be asking some questions about whether my department is fit for purpose.”
The dispute began in 2011 when Mr Lamont’s Incapacity Benefit was moved to Employment Support Allowance due to changes at the Department for Work and Pensions.
Since then Mr Lamont and Dr Powell, who has helped thousands of people with industrial disputes and benefit complaints, challenged the DWP on its handling of the case, saying:
•In January 2012 JCP did not tell Mr Lamont that his benefit would be reduced by £33.25 a week when it was transferred to the new system.
•JCP did not tell Mr Lamont that his benefit had been stopped in January and September 2014
•JCP incorrectly said that Mr Lamont did not attend an ATOS assessment about his ability to work in September 2013.
•JCP did not provide a timely response to Mr Lamont’s complaints.
The Independent Case Examiner upheld all the complaints, recommending JCP apologise and make a £350 consolatory payment.
Dr Powell said: “It is scandalous and how many people in the country are in the same position as Mr Lamont but don’t have someone to represent them.
“The DWP’s procedures need looking at so they are more complainant friendly and their sections need to communicate better with each other.”
A DWP spokesman said: “We are sorry for the handling of this benefit claim, which did not meet the high standards we expect. We have apologised to Mr Lamont.”
Mr Lamont’s unpaid benefits were backdated at earlier points in the proceedings.