Bad service deliverance

On the 7th September I went to the store in south coast mall to buy 2 pairs of shoes for my son, well I didn’t check the sizes on the shoes but only checked on the tags. So when I got home I only noticed the 1 pair tht it was 2 different sizes and I put it aside to get it changed the next day, bt then the next day(the 8th) came back back with the 1 pair of shoes torn and then decided to just take both shoes back. To my surprise when I got to the store on 9th they did the exchanges and all was good, however after 5min of leaving the shop I get a call that I must come back to the store to sign 1 document and I told them I wil come when I’m done at checkers, to my surprise when I got out of checkers the shop assistant was already waiting for me at checkers and I was escorted back to the shop as if Ive ****** something, no worries still and when I got to shop I’m told they can’t exchange the torn shoes coz it’s not the same size as the label, to my surprise I was not even aware coz I just got home I put the shoes aside and ready for my son’s PE day as they wear sport clothes. Then I tell the ladies I bought the shoes tht I got from the store the day b4 n still had the tags sadly I did not bring them coz they at home. And I was indirectly told that I’ve brought in shoes tht weren’t even those that I’ve bought and trying get myself another pair for free. I bought those shoes on account and if I wanted I could have bought more and yet now they regard me as a ***** when it was their error tht the shoes where incorrectly labeled with poor quality and yet the fault was with me. Non of them in the shop tried to sort the matter but kept it I should bring the correct shoes and yet they were very happy for let me leave the shoes without even a refund or exchange but refunded me for the other pair.