Mr Price Refused to exchange item after a day of purchase

Went to Mr Price Atlyn Shopping Centre on Wednesday 10 Aug 9:55 and purchased two pants for my daughter, the total purchase transaction was R609.97. The experience with purchasing was first of all not a good one as one of the pants I was purchasing didn’t have a tag so I went back to take different pants of the same make with a tag and that in itself was a struggle as most of the pants on the rail didn’t have tags. After that the till I was initially purchasing at had issues and after the whole process had to be moved to another till to pay. I left the store and returned on Friday because the pants size was incorrect and the swap would have happened when looking for pants with a tag as two of the pants I found had no tags. When I got to the store on Friday I was welcomed by a rude lady that told me that they cannot assist me with exchanging the pants size as the pants I had didn’t have a tag and because I didn’t have a receipt. I showed her the bank card transaction on my phone and asked her to please reprint the receipt as I have the date and time and not sure if I requested the receipt paper print or email receipt as I didn’t get the email and also couldn’t find the receipt. She only checked with my email address and said there’s nothing and that she can’t help me. I don’t understand why the store would sell items without tags and inform me that i can’t return items without tags when it was bought like that. I also asked her to go back to the cameras if necessary and she also told me that there’s no cameras in the store. The whole experience was simply awful and I cannot accept that now I have to be stuck with pants that I cannot exchange due to the stores fault