Builders Warehouse Bad Customer Service

I bought 2 x 20L Buckets of DULUX (****** Glow 2) paint at Builders Warehouse Woodlands around August of 2018. I immediately used one bucket to paint my walls and around November 2018 I wanted to use another bucket to do the second coat, but the colour came out funny, not the same as the first one. I then went to Builders Warehouse Woodlands to question this and was sent from pillar to post and told that it is Dulux's problem and not Builders Warehouse (By the way I bought the paint at Builders). I kept my cool and waited for four weeks before the Dulux Technician came to my site to check what the issue is, he confirmed that it may have been the nossle problem during the mixing that one colour wasn't added correctly and promised to replace the paint with the correct one. Till today, am still waiting and Builders Woodlands promises to call me back to come collect the paint everytime I call. They never come back to me etc. They really have a bad service especially that paint section under the leadership of IVAN. I still want my paint and this is delaying the completion of my project, if I can't get the paint then I want my money back.,