Atwal, 45, was in his shop when the gang attacked and lost his life on the road outside while trying to apprehend one of the convicted.
A struggled ensued which caused the robber to push Atwal who fell into the road and into the path of an on coming lorry which was unable to stop in time.
His wife, Damanjeet Kaur, was present in the business premises during the incident on 14 October 2013.
A statement on behalf of Damanjeet Kaur said: "Shammi was the most loving husband and father. Since that Monday I don’t know how to cope or live anymore. My life took a 360 degree turn. We have lost the children’s father, my husband and it is very hard for me and the children.
“This is something we will live with for the rest of our life and I will see my kids grow up without their dad and I am finding that very hard to cope with. There are no words to express how we are feeling - we are just living. We miss him all the time and always will".