Worst service I've ever seen from such a big supplier

I bought a paint supplied by Stevenson paints at a certain hardware store. Their product Franklin Hunt showed me wonders. After two weeks the paint started peeling off and unfortunately at the front. I became so frustrated, and contacted the hardware which couldn't help but communicated with a technician from Stevensons. I was told my wall was damp which I disagreed on. My question was if I was crazy enough to paint the damp wall then why is it peeling at the front only? They lady tried to help me by compensating me with a 5 litre which she claimed she bought it from her pocket. That told me that they company wasn't prepared to meet my complain. I bought two 20 litres and was given only 5 litres which cannot cover an area that is damaged now. I'm so stressed knowing that I have to buy other two 20 litres and pay for labor. My money went down the drain and nobody seem to care. Now my house looks like an old vandalized house. They hardware and both the supplier benefited from me but it was a huge loss for me. Their services is bad, in a way that I also tried to contact someone from their offices via emails, at first there was good communication but now the gentleman is nowhere to be found. I emailed him but he doesn't even bother to respond. I would like the other customers to be aware of paints from Stevenson before they encounter the same problem. I can't understand how can a company that has been here since 1979 CA offer such service. I'm very disappointed and frustrated.