I just don't want anyone will be cheated like me, therefore I post hte message here. In fact, I have already given up my deposit and book alternative accommodation in Oxford. VIP Backpackers sold me the accommodation which they are not affiliated with. Here is the hostel sent to me days ago.
"Hi Wenyi, Unfortunately we are not affiliated with VIP backpackers and I cannot accept your booking. We did ask VIP Backpackers to take us off their site, and they confirmed that our account was deactivated, yet it seems that they are still taking bookings for us. I have tried contacting them numerous times since receiving your booking, however have not been able to get through. Perhaps you will have better luck. I will keep trying but I do suggest that you contact them and get your deposit back. "

Then, I tried to contact with VIP Backpacers many many times in some ways like leaving messages on their website, facebook, twitter and sending emails. After a few days, they finally replied to me. They just take delaying tactic and don't resolve the matter. Even though I told them I have mailed to the ACCC, they merely replied "Hi Wenyi, I am sorry for the delay, I am waiting for a response from the ACCC, it’s a shame it had to come to this that early. " They still don't do anything.