Manager Refused To Return Shoes

On the 6th of December 2019 I went to Eastgate Mall to purchase a pair of shoes which on the day I was attending a conference at work. I was the first customer in store at the time when I purchased a pair of Uzzi shoes at Truworths Man. When I fitted the shoe it was a perfect fit and then took it. During the cause of the day I started feeling uncomfortable to a point where I had to take them off and wear my takkies which was not part of the dress code. Basically I worn the shoes for less then 3 hours when I couldn't bear the pain on my small toes on both sides of my feet. Once I was done I call the branch and asked them if they by any chance have a bigger size them the one i have taken. The lady whom assist me over the phone was very helpful and professional. When I got to the branch to return it for a bigger size, the store manager did he wouldn't take back the shoes and there nothing he can do about. But I explained to him that the shoes has been even worn for a day or weeks I bought it here this morning the very same lady whom help over the phone was my witness but he totally refused to exchange it for a bigger size. The shoes aren't damaged or any defects but he refused. This was so unprofessional that he didn't even bother to make any efforts to call whom he said was his manager or had office and that he will be back on Monday that's when he will deal with my matter. But I said so I should wait for you to return on Monday while I have a issue with good I'm not happy about and just wanted to exchange them for a bigger size since I really loved the shoes. The shoes were left at the store and I kept my receipt.