Legal Question in Consumer Law in Texas

Not without a fight. The Defendant will have a number of excuses. There probably is language in the contract saying that the estimate is only that and the savings will vary from customer to customer.

You can send a Deceptive Trade Practices Act Letter, and potentially (maybe, if everything is done right) recover attorneys fees and costs. Probably not enough is involved to get an attorney to take your case on a contingent fee, unless you are joined with a number of people who have the same type claim. Look in Google and see if you can find someone who is handling a number of cases.

Good Luck.