It is very unlikely that you would be arrested.  You have a dispute about a debt, and there is no crime involved in that.  (It can be a crime to commit fraud by passing a bad check, but that doesn't fit your situation, and it is highly unlikely the police or da would issue an arrest warrant even if the car shop owner doesn't correctly describe the facts.  Perhaps you can remind the guy that if he has you arrested on false facts he will be liable for false arrest.)\n\nWhat is more likely is that he will sue you.\n\nResponse to additional info/questions:\n\nHe can sue and continue to collect.  You should write to the collection agency, and tell them that you did not recieve the services contracted for from the garage, and there is no valid debt.  Tell them to remove any negative reports about your credit (and tell the garage owner the same.  It is a violation of federal law to report a bad debt to credit agencies of the matter is in dispute.)\n\nIf he sues you, make the appropriate motion in court to stop the actions of the collection agency until the matter is settled.  Threaten to countersue the garage owner if he does not stop the collection agency and fix any harm to your credit.\n\nI don't know how much the bill is for.  Dealing with this in court may end up being more expensive than just paying.  The advice to consult a lawyer is good.  If the garage is a AAA affliated shop, and you are a member, they have a process for resolving disputes.  (By the way, the major credit cards do too -- if you had told Mastercard or Visa to stop payment, then he would have to battle the credit card company to get it, at least til they investigated and disagreed with your position.)