Where can I find a lawyer for a contractor dispute?

The extra payment demand is only one part of the dispute, because the unfinished work may already be costing the business money. There may also be an arbitration clause or notice requirements in the contract that affect what you can do next. You can contact a commercial litigation attorney here: https://arkadybukhlawfirm.com/practice-areas/litigation/commercial-litigation/ . Bring the signed agreement, invoices, payment confirmations, and every written change request to the consultation. A clear timeline of the missed deadlines and unfinished work will help the attorney assess the case.

Don't let the argument carry on through scattered calls and texts, because it gets harder to establish what each side actually said. Send one written request asking the contractor to explain every extra charge and state when the remaining work will be completed. The New York City Bar Legal Referral Service is a sensible place to ask for an attorney who handles contract and construction disputes. Give them a short outline of the problem and the amount involved, and they'll direct you to the right type of lawyer.