 "An insurance agent who undertakes to procure insurance for another owes an obligation to his client to use reasonable diligence in attempting to place the insurance requested and to notify the client promptly if he has failed to obtain the requested insurance. The client may recover from the agent the loss he sustains as a result of the agent's failure to procure the desired coverage if the actions of the agent warranted an assumption by the client that he was properly insured in the amount of the desired coverage." Kiernan v. Commercial Union Insurance Company of New York, 