Late reply to urgent request costing the customer

One is told that they will give a quote with regard to changing or canceling a flight on the same day as booking the flight I asked would the quotation come on the same day and was told yes it would it did not arrive so on the day after I made two phone calls only to be told now you will have to pay a fee that I feel is excessive and when asking to speak to management they say they have to escalate the request who knows when management will call