Transfer of property under trust

Hi, My Father has a shop that is under a trust. Now, We want to sell the shop. However, the main trustee has taken large amount of money from a property dealer for the promise that he will transfer the receipt only on the property dealer's name and won't allow us to transfer it to anyone else's name. Now, what can we do. and what are our options if we want to sell the shop as the property dealer has already lowered the value of the property much below the market price due to his deal with the trustee.