BookMyForex – Never pay 2% charge to block the exchange rates

I tried to sell dollars which I bought from them sometime back. While booking they charge 2% of the total value to block the exchange rate which is refundable. I booked it thought their portal on Sunday at around 11 am. But they didn't send the agent to collect the cash. I had my flight on Sunday midnight. Then on Monday they called me and sent me an email that they will cancel the request and I will be charged that 2%(so they will not refund). I even replied to them explaining everything. This is a scam. They clearly say if you book before 1 pm then someone will come to pick the cash.