Bad customer service for a pensioner

My grandmother bought a school bag to another branch when she went to return the bag because she took boys bag instead of girls on Saturday 23/07/22 went to atllyn shoprite in atteridgville she found a lady who was wearing a controller belt which she told my grandmother she must return the school bag where she bought it as old as my grandmother she left with no transport money to go to another branch where the bag was purchased and my daughter needs the bag for school on Monday I'm not happy with service and treatment my grandmother received and what is shoprite exchange and return policy because that bag was bought on 18 july 2022