Legal Question in Consumer Law in California

You did not get a canned response. You got a very good response based on the facts you gave at the time. With the further information and detail you have provided, you would have gotten a different answer. My opinion based on the further information, is that your question still is incomplete and unclear. You say the receipt or contract says x amount of carpet for x dollars, but then you go on to say you paid "the bottom line figure. I did not check the addition and still have not checked it." That suggests that the line items are on the document, as well as the total. That distinction is a crucial one. If all the contract says is literally x amount of carpet installed for x dollars, then the contractor has no case. If the line items are listed, however, and then the total, and if anyone who looks at the document can see that the line items total $1,000 more than the bottom line number, you and the contractor have a legitimate dispute over the meaning and intent of the contract. A contract that contains crucial contradictions right on the face of it, and one party sues to enforce their interpretation of what the real meaning of the contract was, the court will have to weigh the evidence as to what the real contract was supposed to be. A court could easily find that you were on notice of the amount of each item and you should pay that, or could just as easily find that since you relied on the bottom line number, that is all you owe. I personally think that since the contractor wrote up the document, they are stuck with their math error, but another attorney or judge could think otherwise, and there are legal theories to support each argument.

Another theory that could be applied to resolve the dispute is that no contract was formed and the contractor must be paid the "quantum meruit" or "reasonable value" of the services and materials. I recall you said in your earlier question that you had another bid that was more than this contractor but less than this contractor's price with $1,000 added. A court could easily find that the amount of the other bid is a good measure of the reasonable value. That might also be a reasonable basis for a settlement with the contractor who did the work, since you say that if he had done his math right you would have gone with the other bid and paid that amount. So you could settle the issue by not paying him the $1,000, but paying the difference between his mistaken bottom line and the amount of the other bid.