Rawsons sale - Property with No Plans

Purchased a house in 2015, I and my wife made several attempts with the agent Salome to get our house plans from the previous owner, as I been to the Municipality in Brakpan and according to them the previous owner of the house had taken the plans of our house. We urgently need to do a extension/alteration on our building but cannot go ahead as we dont have the original plans for the house we purchased. Property was sold to us without plans, and when we asked we where told to get a copy from the municipality , which we tried doing however no plans for our property are currently with the municipality.

We urgently need help .....!

Regards, Mr K Singh