I've dealt with a string of cases where claimants have asked for an increase in their PIP only to have it removed entirely. Probably the most ridiculous case was that of Vic Holmes who has agreed for me to mention him here.
Vic notified the DWP of a change of circumstances in that his needs had increased due to strokes. The DWP sent an agent to his home resulting in a report being produced that the strokes had improved his health so as to take him entirely outisde of PIP eligibility! Well I'm not a doctor but I had never heard that strokes could improve the condition of a patient. And, even if it was possible, the claimant had clearly stated the strokes had caused him to need more support.
Furthermore, what came across as an opportunistic removal of an entitlement, was done at a time the DWP had been informed of the death of Vic's partner who had assisted him with all paperwork. And yet letters continued to be sent to her creating the impression the DWP believed even deceased partners of PIP claimants still absolve it of the responsibility of proper benefits administration.
DWP Officials refused to put matters right until the Treasury Solicitor was asked to assist. And Vic finally got his benefits increased as should have happened without me, or the Treasury Solicitor, ever having to get involved.
The DWP, if left to its own devices, would have almost certainly forced Vic through the entire appeals process (about a year) before his entitlement was restored.