Is there such a thing as overpriced service?

[Marat Turgunbaev]

I had a toilet overflow in tenants' occupied property the week after the new year. It was hard to reach anyone quickly so I had one technician from Roto-Rooter Plumbing who told me the problem was a clogged drain near the septic. He asked for $828!!! just to remove a clog. I agreed since it was an urgent thing to let tenants use water. A month after, toilet overflow happened again. The other technician that arrived told me that the septic pump didn't work due to electrical wiring issues and needed to be replaced. I replaced it with a septic company for $1200, but then he left the electrical cord outside saying it was only electricians job to properly connect the wire to the breaker box. Now I need to spend another buck on that. 

Here are the questions: 1) it seems the price for cleaning the clog was very pricey, is there any way I can dispute the fee with a company, even post-service? 2) Is it more likely that from the beginning the stoppage was caused by a dysfunctional pump, but the first plumber just took advantage to charge for that? 3) weren't the septic guys supposed to do the electrical work as well? Do you have similar experiences and how did you deal with them?