What Is The Purpose Of Paying Deposit

I have made a booking with FOREVER Tour Agency (located @ Nibong Tebal) for a six-days trip to Hong Kong two months ago. Deposit of RM1500 has been paid for three person to confirm the booking.

We were very excited when the date is soon approaching.
However, the condition of my bro-in-law as well as the new Swine flu virus which has swept the globe in recent months stopped us from participating the trip.

So, mom has contacted FOREVER as we would like to drop the package of three. Guess what we have been told...
We've got to pay RM1000 EACH as the compensation for not joining the trip. Reason is, tickets have been issued and customers have the responsibility to bear the ticket fees. The worst part is, even if you would like to postpone or change the trip to other location, still, you must pay the RM1000 as the ticket has been issued to the location that we first booked.

AND, my mum, who is a very kind-hearted lady has paid them RM3000 after their so-called "explanation".

WHAT IS THE PURPOSE OF PAYING DEPOSIT AT THE FIRST PLACE THEN???!!?!?!?

From my understanding, that should be fees to the company where the customer didn't show up at the very last minute.

#$^&%*(*&^%$#%$
I'm so damn pissed out right now!!!!