Evening all. Looking for some advice, though I'm not sure if there's actually anything I can do. We recently hired a plumber to do a complete replumb of the whole house, including fitting a new boiler, new radiators, taking out a back boiler etc. I asked around for personal recommendations and someone who I'll call K came highly recommended so we asked him to do a quote. He came, had a look, and told us it would be a two man job so would come back with his partner, J. The two of them came back and gave us a good quote, so we decided to go with them.
When the work started, J came back by himself and told us that K "had had to take his wife somewhere" 
but would be around. We never saw K at all, though J's teenage son did help him out from time to time.
Things started fine. J was a bit hit and miss as to when he'd turn up, but he did work a lot of evenings and weekends to make up so we didn't really mind (we weren't living in the house at the time). He took out the old copper water tank and a load of copper pipes and piled them in one of the bedrooms. A few days later I needed to paint the ceiling in there and got fed up moving the pipes so I could move my ladder and chucked them out of the window. We came back the next day to find that the copper tank had gone, and when I quizzed J about it he told us "a gypsy came and took it". I was so surprised that it took me a while to work out that he must have panicked when he couldn't find his big copper stash and called a contact to sell what was left, since he made it sound as though his gypsy had just wandered past, but we live in a cul de sac in a hamlet which is effectively a large cul de sac, so not exactly a lot of passing trade. He also took a gas fire which had been in front of the back boiler out of the skip. He told me that the gypsy had given his son a tenner in exchange
We were a bit annoyed as DH had been told that the copper would be worth a bit and we'd been planning to sell it ourselves, but put it down to a misunderstanding as we'd never specifically discussed who would have the copper that came out. It did niggle though that he'd told me he only got a tenner for it, as I was pretty sure that that was a lie.
When he installed the boiler, he told us that it was recommended that we have a large magnet called a magnetron installed as well, which would cost £100-120. I told him I would discuss it with DH but if I didn't say otherwise then assume we wanted it. I therefore assumed one had been installed and added £100 to the money we gave him. When I asked him if the money was correct, he was a bit evasive and said he couldn't remember - again I got the impression that he was lying but it was 9 pm, he'd driven 20 miles to get his money and we were in the thick of moving so ignored the niggles.
Since then we've been waiting for him to come back and install our shower (had to get the bathroom tiled first), which was supposed to be some time in the past week. No sign of our shower but we realised a couple of days ago that the pile of copper pipes, which was still in the garden as we hadn't actually got around to scrapping it 
, and a cast iron fireplace which we'd removed from one of the bedrooms and left in the garden (we are the street skanks ) had both been taken in the past week. This is completely unsubstantiated, but I'm wondering whether he came round to do the work, saw the scrap and thought he might as well have it, bearing in mind I know he has a contact and I don't feel he's particularly honest.
Sorry this is so long
My quesions I suppose are: (1) AIBU (2) is there anything I can do and (3) do I mention it to the acquaintance who recommended K in the first place (or to K for that matter)? I feel I ought to tell her but would feel a bit embarrassed/as though I was accusing her.
Thank you for reading if you got to the end!