Bad quality paint and extremely bad customer service

We bought the Builders name brand paint from Builders Meadowdale and painted a room during Lockdown. Whilst 3 walls of 1 colour was good, the one wall colour peeled off the wall when the masking tape was taken off. I went to back to Builders Meadowdale and as there was no customer service open, I was advised to go to the paint department. I explained what had happened and the people at the paint department first of all tried to tell me that I did not know how to paint, then tried to sell me Wall and All paint instead of the housebrand. I then told them that I actually do not feel I should pay for another litre of paint as the mistake was clearly the paint - if 3 other walls worked well why would this be different, the walls were all treated the same way. They then called a manager who in between walking around serving customers, took my name and numbers as well as a copy of the slip and promised to contact me so they can come look for themselves. Three days later not even a courtesy call.