Challenging *very* old DLA overpayment

So I’ve got a client with a very old DLA overpayment (dates back to around 2011) when they went into hospital and failed to notify the DWP promptly. I’ve tried a very long shot Anytime Revision request on the basis of official error (basically they had an appointee and due to the nature of their hospital stay not being voluntary it wasn’t practical for them to contact the DWP themselves). Fully warned the client that this is long shot territory but with nothing to lose might as well try.

Fast forward a few months and I’ve had a phone call from DLA telling me that all the records have been destroyed so there’s nothing they can do. Only thing they could suggest is a complaint. I was slightly startled to hear all the records are destroyed because I did SAR before starting down this path and they were able to send me quite a lot of records!

But, taking them at face value, does anyone have any tactical suggestions? Should I just complain as they suggested? Is there some other tactic I can take I the DWP are recovering a debt they can no longer apparently evidence if they’ve destroyed all the records?

I expect the DWP are using the DLA summary record held on their CIS Searchlight platform. As it appears the client was lacking mental capacity you could try getting a support/social worker to complete a DMHEF and send to DWP. I understand that HMRC wrote off some debts in this situation though DWP will be more difficult !
https://www.businessdebtline.org/documents/debt_and_mental_health_evidence_form_DMHEF_pack_with_instructions_BDL_EW.pdf

Ah that’s a good suggestion but I’m not sure they ever lacked capacity whilst they were actually in hospital (certainly the notes I’ve seen don’t refer to any such capacity concerns). It was the restrictions placed on them during their stay that meant it was difficult for them to manage their affairs and required an appointee.