I need answers

I would like to find out what is the proper procedure or process when buying a house. In May 2018 we went for a viewing on a house being sold in Electric City Eersteriver Cape town. The estate agent is Andile Snam he works for Realtors. We signed that same month for the house however we were told that we need to wait on an executive letter from the sellers because the house was a late estate house. Fine we waited,3 months later just to find out the house was sold on the 29 August 2018. No one contacted us except the lawyers saying they withdrawal from the process as it was taking to long. Why hasn't the agent contacted us,we have been asking him every single day for a period of 3 months and all he could say is that his still waiting on the annoying letter. We signed a contract, went for the bond and even toke up bond protection. We were the first to view and to sign. I am very disappointed in Realtors and feel that the treatment is so unfair because if we were told earlier we would've looked somewhere else.

Really feel frustrated and annoyed