house work overcharge

Under our home there are 50 piers to support the home. Under each pier is a wooden pad.
Recently a company replaced the 50 wooden pads with 50 ABS Vinyl pads, and leveling
each pad. The job took 2 men 2.5 hours. We were charged $2400. From the Internet, I
learned that each pad cost about $10, for a total of $500 for the 50 pads. In Hemet,CA where the job was done, a construction worker's hourly wage is <$20/hour. So, the total
labor cost would be <$100. So, the total cost of Labor + parts should be about $600.
I feel we were overcharged by about $1400.

Hoe do we get that amount back?

Well that is hard to do now unless you never agreed to the work and price?

Has you agreed tot he charges in advance or what was the deal?

Thanks for your response.

The company claimed that we had a "3-days to cancel" provision in the contract.

But that was never stated either in the contract or in words.

If we had known that, we probably would have cancelled the job.