My parents bought a bungalow in November. My dad is 75, my mum is younger but has arthritis and could no longer manage the stairs.
Vendors were lovely.
Had basic homebuyers survey done. No problems.
They move in. Week One water starts pouring through a window when it rains. 
Builder/window man comes out and does some stuff. Problem moves but isn't resolved.
More stuff is done, nothing resolved. Extractor fan is opened one day, kitchen fills up with water.
Vendor ignores their many calls.
Solicitor want £174 an hour just to look through the paperwork to see if any money can be recouped.
Parents make plans with a local builder to have the roof re-done first and then a new bathroom. Builder is a cunt. Keeps saying he'll ring/turn up then doesn't bother. Decides he'll do the bathroom first despite what they've asked and basically acts as though he's doing them a favour. He's not. This has been booked since December and he's charging a large sum of money. Has also strung them along saying he has his own scaffolding company and similar but later says he needs to hire them from elsewhere.
Went round there last week. Most ceilings/coving/tops of walls are black with mould. Duvets, clothes, carpets, etc tinged with mould.
They're miserable.
Today they tell me that they're going to sell. At a loss seeing as the roof is badly in need of sorting.
:(
They've cancelled the builder.
They plan to scrub off the damp, smarten it all up with nice fresh paint, new carpets and hope someone who doesn't mind getting the roof redone and a couple of windows refitted.
They'll be entirely honest with any buyer, because that's how they are.
I'm so fucked off. These are my elderly parents. I feel like they've been royally duped. Which they have. I'm really upset for them.
I'll help them get it nice ready for selling but I don't want them to have to do this. They've only just moved and that was really hard for them.
What can I do? What will help? Who can I call??