
I disagree, you wouldn't have got the same results yourself. Yours would have been better because you care about your carpets.
However this guy sounds like a right bodger. If I had done that job and worked my backside ragged with the TM, not moving much furniture around, I would have been a little longer than this guy. No way on earth with a portable can you do that much in that little time and call it a proper job.
I would say call him back but what is gonna happen? He'll probably want to "go over it again" as a way of paying lip service to your complaint. I wouldn't let him anywhere near the carpets again.
Carpets still wet after that time is seriously wrong - if you can, lift a corner and have a look to see if the backing or underlay looks damp. There could be a problem over the next week or two with mildew/mouldy smell if so.
There should be no foul smell after cleaning - only if there is wool in the carpets should they smell a bit strange, just the smell of wet wool, which should die down over the following day or two.
I hope nobody comes and sticks the boot in to you over this because you don't need it at this precise moment. But (as nicely as I can

) this guy's price was on the cheap side.... doesn't mean everyone cheap is going to do it that badly, some guys genuinely try to do it the best they can but simply don't value themselves high enough. Most experienced cleaners, truckmount or portable makes no difference, would probably be charging in the £220 - £270 bracket for around 800ft² plus a flight of stairs.
I think (this is not really aimed at you but just a general statement) there is a lot more chance of finding a good cleaner charging higher prices than lower ones.
Probably 7 out of 10 charging £250 would have done a good job
Probably 3 out of 10 charging £160 would have done a good job
Just my opinion.
Do you reckon you could get your money back off him?