You got out of paying for the storage tank and the installation labour, or just the tank?
There was a bill of over $5000. I paid $0. So both tank and labor, and some other stuff.
I always negotiate the entire job in detail before I agree either as a customer or as a vendor.
My wife did. She even had set up a payment plan with the plumber.
I would rather lose a sale then have to deal with a difficult customer who tries to get something for nothing. I don't like to rip people off either, I pay my debts. My policy of pure honesty and above board dealings has always worked for me, any updates on the job are clearly laid out as well before I do anything different than the original deal.
I have been tricked by "confused" customers exactly once. I have had a difficult customers. They becomes "cash in advance only" but only after proof of being bad dealer.
That only works when you deal with honest people.
I paid them $2700 up front to dewinterize a place, get the heating system up and running, and cap the supply and drain for 12 sinks. I only had to pay 1/3 up front. I will never pay 100% upfront again.
After doing that work, they said a couple other things needed to get done. It was supposed to be around $2100, and my wife made an agreement that we would make four payments of about $525.
Over a month goes by, and no bill. We had asked for a bill multiple times.
We move to the place on a Friday night. On Monday morning I go to the office of the plumber, and ask if I can have the balance of my account. They say there is no account for me or my wife in the system, and also nothing for the property address. I leave my name and phone number.
I get a phone call about an hour later, and it's the manager guy. I asked him if he had seen some utility sinks that are missing. He said he did see them at one point, and makes an appointment to visit me the next morning to go over the bill and explain to me what was done. I had never talked to this guy before, so it was kind of weird that he wanted to talk to me, and not my wife. I didn't make any agreements with him.
Anyway, he shows up the next morning. We go down into the basement, next to the missing utility sinks, and the boiler, hotwater tank and that stuff. He hands me a bill for the hotwater tanks, and says "I'll let you open this". So I am looking at a $1500 bill, but it has my general contractors name and address on it. I didn't say anything.
I asked him about the sink. He failed to mention that his company had capped the drain line and done some other things to cover up the theft, and they were charging me for it.
Within a few days we let them know we would be disputing the bill, and they would need to provide an itemized list of the work that was done, and associated charges. We always said we would pay the $2100 we agreed to.
After about a month we got the first official corporate bill, with our name on it. The only thing on the bill was an amount.
My wife contacted the corporate office, and some operations manager got back to her. He was acting like a dick at first, but he was able to find out some info for us. He was able to tell us that they did cap the drain line to the utility sink. After he looked into it for about a week or two, he said he was making our account balance zero, and apologized.