STD blues for OC Migrant

My single parent (male) client has lost a lot of money after migrating to UC. He was receiving ESA (SG) with SDP and child element. His (only) daughter moved out to live with Mum and then moved back again; he reported each change to the DWP.As a result of the Change of Circs he was migrated to UC and lost his SDP. To compound his problems his daughter moved out again and he was hit with bedroom tax.
He has already appealed against the loss of SDP but I can’t see any chance of success until the new regulations for transitional payments come into force. Does anyone know when this might be?  Also, should I advise him the withdraw the appeal?

There is no child element in ESA.  I think what has probably happened is this:

1. He was on ESA including an SDP and also Child Tax Credit
2. His daughter moved out, so his Tax Credit ended.  This ought not to have prompted a UC claim at any time; moreover if it happened since 16 January this year he could not have claimed UC even if he wanted to.
3. His daughter then moved back in and he needed extra income to support her.
3a. If it was still pre-16 January, the only means-tested help available to him to support his daughter would have been UC so his choice was either to claim UC or do without.  He decided to claim UC and this meant that his ESA and HB both ended.  Despite losing approx. £40 a week off the adult elements by switching from ESA to UC, this was still the better buy at the time because the amount of UC he gets for his daughter exceeds what he has lost from ESA.  Housing element/HB is the same either way.  There would be no point in appealing this as what happened was correct.  In due course, he will be in line for partial reimbursement backdated to the start of the UC claim - this remains in draft and is bogged down with the managed migration regulations
3b. If his daughter returned since 16 January this year, it’s different.  At this point, having an SDP in both ESA and HB meant that he was not allowed to claim UC.  If this happened, it should be possible to revert to ESA and HB by pointing out to both the DWP and HB that they have made a mistake and he was entitled to an SDP when his daughter moved back in.  He will also need Tax Credits to accept a claim and backdating will be an issue - might have to pursue a complaint and compensation claim against DWP for wrongly allowing him to claim UC.

I think it would be unlikely (not impossible) that both HB and DWP failed to spot an SDP claimant and allowed a UC claim to go ahead without anyone flagging it up.  I therefore suspect that version 3a is correct and so he has the right benefits and no arguable appeal case that I can see; but if he is still on UC when the SDP compensation scheme finally goes live he will at least get back about half of what he has lost.

Bedroom tax would have happened in any case (HB or UC - makes no difference): DHP is the only solution for that.