No longer want the loan

I took up a quick advance and have made an mistake with the payment date and now either want to amend the date or cancel the loan as the payment date is before my salary date. I am told by the call centre agents that I need to wait for the money to be paid into my account, ask for a settlement amount then repay with interest as they cannot cancel! That is ****************! I no longer want the money paid so why should they paid it by force and charge me??? I am told if I had called in, they would have been able to either change the date or cancel this loan!!