If that is the case then I think you have very reasonable grounds for a grievance, You should contact the company owner via a phone call and talk it through with him. Don't call all heated and storming into an argument, cool, calm and collect, but don't be afraid to mention that you feel duped and your looking to the company to either explain the cost to your satisfaction or come to a credit agreement.
If you called specifically for a faucet replacement and they spent time (possibly billed time) working up a quote for all sorts of other repair work, this would constitute unfair trade practices, the
ONLY work you should be billed for is the faucet replacement. Ask the owner/manager of the company to give you an ITEMIZED bill, you are entitled by law to ask for and be given an exact record of how the cost was derived (labor, materials, travel time if applicable). Make sure when you call to speak to someone in authority that you document the time, date, who you talked to and the conversation itself.
If you still cannot reach a suitable and mutually agreeable solution you always have the right to take your grievance to the Better Business Bureau in your city/state.
One thing I must add is don't be disillusioned by a bad contractor, for every one bad company there are 20 great ones.
