company bieng non compliant and undermining customers

Hi yesterday i went to Sportscene Westgate to exchange a jean for my girlfriend because she got it as a birthday present,so unfortunately it wasnt the right size,when i got there to exchange explained the matter to tshepo the store manager...that guy gave me one hell of a attitude because honestly how many people get presents without a slip and he refused to do so,he was going on for himself,peforming and that!!!,i came very far to exchange the jean,waisted alot of money and i was with the child amd all of this happened in front of my daughter in law and thats not a very good experience for a child,my girlfriend was very angry yesterday because she is a big customer for Sportscene so please help to stop this and i need a very serious apology for this and they went agianst campany policy,they find a way to put back a smile on girlfriends face or i wont stop.please help us fight this its out of control!!!