Liberty midlands Mall shocking after sales service !

I purchased 2 pairs of Puma tekkies. My son wore once and the material on one pair started to bubble ! I returned the quite obviously faulty pair to be told I had purchased the wrong size and that's why they are bubbling !! The staff are rude and unhelpful ! I am not backing down and will take this matter further ! Guys don't waste your time buying inferior goods with no after sales service...it seems to me like Tekkie Town hold there staff responsible and deduct from their salaries if goods are returned which I am sure is ******* !!