Legal options for enforcing property sale agreement after expiration and buyer delaying

Hi all, I entered into a sale agreement for a property with a buyer three months ago. However, the sale agreement has now expired, and despite repeated attempts to contact the buyer, they are unwilling to proceed with the property registration. The buyer is showing no interest in completing the transaction, and I am unsure of how to move forward. The sale agreement does not contain a specific penalty clause, except for a reference to the Specific Relief Act /Specific Performance Act. Given this situation, I would like to seek your advice on the following points: 1) What legal options do I have to compel the buyer to proceed with the registration and complete the sale? 2) Would sending a legal notice be the best course of action to demand the completion of the transaction, or should I consider any other legal measures? 3) If the buyer fails to respond to the notice, can I ask for a refund of the advance amount, deducting a certain percentage (e.g., 25%) as compensation for the lost opportunity of other potential sales? 4) What are the potential legal ramifications of the buyer's failure to proceed with the registration after the agreement has expired? 5) How can I enforce my right to claim compensation for the delay or cancellation of the transaction under these circumstances? Your insights and advice will be greatly appreciated. Thank you in advance.