Yes, based on what you write, the installer has breached or violated its contractual (the agreement between you, whether written or oral [i.e. unwritten]) obligations by not installing the carpet when they were supposed to. When one party breaches a contract, the other party can treated the contract as terminated, or canceled, due to the breach. Also, the breaching party cannot keep the other party's money; they have to return your deposit once you cancel. If they do not, you could sue them (e.g. in small claims court) for the money.