Got them out to look at dishwasher that was not draining. Turned out to be in the hose under the sink. But they wouldn't fix it, as it's not something they do. So most of my included half hour (that comes with callout) went to waste. Next time I'll look for a plumber that also fixes dishwashers.

Oct 11 2017: final update about these appalling shonks before I put all this behind me. They finally got back to me and verified my membership cancelation. As for "conducting a review" that's come to nothing, just a stalling tactic.
Bottom line: do not under any circumstances have anything to do with this company.
end update
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I feel rather ashamed (not to mention ripped off) [Retracted inflammatory comment]. A tap needed replacing (hot and cold together, so a bit tricky). The guy from The Plumbing & Electrical Doctor comes around and quotes $598 including $199 membership, or even more (ie over $600) without membership. Then goes through a rigmarole we've all seen on telly (though usually involving used a car salesman): he knocks $100 off, saying he might get in trouble with the boss for this but he'll wear it. I kind of rolled my eyes at that, but I needed this done today. These taps probably cost a bit, I thought. And if I'd refused, of course there would have been a call-out fee.
So I became a member, it took him 10 minutes to install; I paid $499.
Then I googled the tap and it retails for $59.95.
In addition, there’s a clause in the one-year membership form stipulating that if you don’t want it to roll into the next year (at $100 per year) you have to cancel it more than a month before the end of the first year! I doubt this can actually be legal. Anyway, I’ve emailed them cancelling it, as there is no way on earth I’ll use this bunch again, even at “membership” prices.
Amazing really. Live and learn. (I don't yet know about the quality so have given it 3 stars.)
Update: now I've seen the other reviews, below. Wish I'd read them before contacting this bunch! And yes, as with some other customers, this guy tried to sell me all sorts of other work, the water tank was getting dangerous, water pressure too high, etc.
Update on 9 October. Have cancelled membership for next year with them in writing four times (by email, online form and Twitter) but am unable to get acknowledgement from them. I fear them taking $100 from credit card in a year's time, and all the rigmarole involved in trying to get it back.

Approximate cost: $500