what is "carpet power buffer"?

That means you had heavy soiled or high traffic areas with your carpets.
Power buffing is a way extra machine (buffer ) to really go to town with the enzyme treatment . I do admit huge difference.
You would probably said he did not do a good job which would have been worse had not he took this extra grueling step but no he did what he had to to agitate and loosen all the soil what ever you had going and mind you you are trying to get your deposit bank . You need to tip that carpet cleaner .Put a smile on your face.

Whats the problem manager after you ?

I think you confused the the 240 the two was a dollar sign .
You assumed and agreed prior to the work . You paid him right.
Carpet had to be very bad dude.  Got pics .

relax

Dispute with credit card . Carpet could have been old  or cheap
wear and tear ) call company wrong charge for the buffer. Be real to him.
Or  You got jacked .

I've used a buffer before cleaning many times (and used to dry clean with just a buffer). I have to admit, the buffer does a pretty damn good job. I can't get my truckmount to my condo so I was using a ninja. With pets and heavy traffic, it was tough getting it cleaned with the ninja but when I started running the buffer over it (pre-cleaning), OMG night and day difference!

Here is a warning though, if you put a carpet brush on the machine it can and will damage the fibers. SO you really should make a judgment call before using it. If it's older carpet and really heavily soiled, then yea, it will make a HUGE difference. But on newer carpet, you can cause fiber damage like you see in traffic areas.

$40 is not too much to charge for a room, especially if it's just one room. The way I see it, it's about my time. It takes me the same amount of time to drive to the client, unload my equipment and load. The cleaning is the easy part once it's all set up. One room $80 and $40 for pre-scrubbing isn't bad. I'm sure the guy was at the job for at least an hour, so $20 for gas and $100 for his labor is about right.

If you're not making about $100 an hour then you should re-evaluate what you're doing. Between costs of advertising, equipment, chemicals, time and your energy, less than $100 is not really worth it.

Hey someone knows good guide for carpet cleaning, I mean universal guide for different situations?