Buyer's Rights for Availing RFO condo units

We would like to seek for your assistance. My friend and I availed a RFO condo as we are promised of a 3 day process for the turn over and that we are allowed to have the unit leased by our own rules as we are technically the owner. We made the reservation and move-in fee. However, it has been a month now and we not heard back anything from the developer. We sent emails for the follow up and they didn't want to disclose the cause of the delay of the process. All of a sudden, my friend received a call from the developer stating that we have to sign anotjer contract agreement rwgarding the leasing process and that the payment of the leasee should be directly be given to him and not to us which is not stipulated in the original contract and the pricing suddenly differs from what we signed up for. We were jeopardized by the developer for giving us false expectations and false advertisement. We would like to know if we can sue the developer and we would like to demand to them a full refund and indemnification for the hassle it has caused us. Your response will be highly appreciated.