Extremely poor service

Several weeks ago I returned three 20 litre containers of Dulux Weatherguard paint to Builders Warehouse at Gleneagles as the colour did not match the sample. I also had a partially used 20 litre of paint that I wanted to return but the representative at Builders Warehouse said that he couldn’t authorise a refund but that he would get someone from the technical department at Dulux to contact me, and then noted down my details. Two weeks later I went back to Builders Warehouse as I heard nothing from Dulux, and spoke to another Dulux representative. He promised to get back to me within four days, so six days later, after hearing nothing from him, I contacted him. He then said he would get a technical representative to contact me – that was ten days ago and I’m still waiting................