Plascon & Makro Sucks!

I bought 20ltr Plascon Paint in 2019 at Makro Ottery. I only painted yesterday with the paint. Plascon does give you a 5 year window in which to use their product. The colour didn't quite come out as per colour label, so I asked painters to do a 2nd and 3rd coat. I then ran out of paint for 2 walls. Went to my local Buco store with label and asked them to mix 5ltr of the colour. It came out darker, exactly as per the colour swatch we initially wanted. Told the paint mixer it's different, but also the true colour. He asked me to bring the empty drum if I said the colour differs. Did that, and he was able to make sense. Makro Ottery label on my drum says it's a mix for 5ltr, yet tint was used to make 20ltrs. So my colour would always be lighter even if I gave 10 coats. He sent me back to Makro Ottery to speak to Plascon Manager. Plascon Manager and Makro Manager says I'm outside the window of the Consumer Protection Act, so I will not be reimbursed. I'm angry because their mixer did his job incorrectly, and I am a customer, irrespective of the time of Consumer Protection Act lapsing.