Is one sinful for refusing to pay for a tooth polishing that he did not request, and was not informed of its cost beforehand, after the dentist suggested falsifying the insurance report to cover the cost?

Allah commanded believers to fulfill contracts and to be truthful in speech and action. Therefore, defrauding a health insurance company to cover a procedure not included in the contract, by misrepresenting it as another covered procedure, is forbidden and considered deception. If the doctor did this without the patient's request, then the doctor is responsible, and there is no blame on the patient. The doctor's act of deception is forbidden, and it is not permissible for the patient to assist in it or approve of this deception.