Rude and insulting customer service

I bought a Tupperware bucket which came with a lifetime warranty from Tramshed branch in Pretoria CBD. The bucket broke and when I returned it the Consultant refused to change it saying we customers break these products purposely. I find this reason very insulting and the Consultant being completely irrational and out of order . Please assist me to exchange the bucket that I bought out of love for its style and quality.