size 5 shoe a bigger cut and i cant wear them as i would like a humpty dumty because that's what the hub thohoyandou want me to look like

Good day i bought shoes in the hub thohoyandou branch on the 29th.i wear size 5 so i got my size and i paid and left since i was on lunch....so the on the 1st wore my new shoes coming to work..as time goes i realize that the shoes are no longer fitting me nicely like its big.so i took the shoes back yesterday the 2nd only to be told we cant assist you as the shoes are damaged i asked how so the lady showed me some marks underneath the shoes so i asked my self how was i supposedly meant to walk wearing the hub shoes ON AIR for them to have assisted i would understand if the shoes are torn or the surface of it had come off but nothing of such...now I'm left with a bigger cut shoe that i cant wear....they just have too find so many to not wanting to assist because one lady says they look dusty and the next thing was that underneath sole is damage because it showed marks that i had worn of which i told them.so i guess i was suppose to walk on air in order for them to exchange