Customer thinks my wordage of “estimate” is the same thing as a quote or a bid. Now he wont pay the full amount.
You should consider preparing a letter to mail by certified mail, return receipt requested, to the customer to set out the facts and to demand the relief that you want. Attach support for your claim such as your contract and invoice, and photos of your completed (but unpaid) work. Make sure that your letter is professional and business like as it may be evidence later.
If need be, consider filing suit in small claims court (assuming that your claim is less than $20,000), using your letter as evidence.
You may have mechanic's lien rights, but you really should retain a construction attorney to review and evaluate your legal position based on the contract and pertinent documents. The right to be entitled to file a mechanic's lien is set out in Texas Property Code Chapter 53, and you really need to make sure that if you file a lien, you have properly and appropriately done so.
Filing an invalid lien could subject you to liability under the Texas Fraudulent Lien Act, and you could be liable for statutory damages of $10,000, or actual damages, whichever is greater, plus attorney's fees. Facing such a claim would add insult to injury.
Good luck.