Salomon Sport is the worse company and they dont really care

Last week I placed online order for my sons xmas clothes, payment was made and delivery was delivered but my sons shoe was a tight fight even though i order a bigger size, I informed Salomon the same day (24/12) but no one responded. I had to buy another shoes for xmas, today still feedback from Salomon until I made a follow up only to be advised the I have to pay for my own courier, the quote is R463 and the shoe needs to be returned within 7 days - I just paid extra for my sons xmas shoe and instead of being refunded I still need to pay for a courier and this shoe was on sale meaning I wont get anything in return -I dont have the money so what must I do with shoe does not fit my son?