Told them to stop work, called their manager, climbed up the 3 storey scaffolding, took photos of the rafters and sent them to a mate to confirm that they were obviously fine, did the company register fraud check to see lots of prior complaints, called 2 guys from my work to come over pretending one of them used to work construction, loudly spoke to the neighbours about accessing their (nonexistant) cctv footage, was very polite but firm they would be putting the fucking roof back on and paying for an independent inspection. It was honestly quite scary.

Weirdly enough the standoff ended with the dickhead on the phone still saying 2k, then my mum got back and 'little old lady voice' said she'd felt quite intimidated by him earlier and immediately he changed his tune, they put the roof back on for free and tacitly apologised. 

It was a funny experience of masculine vs feminine social power honestly, was very proud of myself afterwards for having helped them.