Disgusting, don't care attitude customer service,

Yesteday (28/11/2023) Went to sam ntuli mall to buy a t-shirt for closing party at work which will be on the 30th November. Unfortunately the size was big, but thinkin i still have wednesday to exchange, i told myself i'll exchange it after work. I check trading hours of the store it says 09:00 - 18:00. Immediately after work i rush to sam ntuli to exchange, i got there literally at 17:45 and i find the store closed, i asked the shop assistance he only made a hand gesture for me to come back tomorrow they are closed. I then asked what time it was since the store closes at 6, he didn't even care about anything not interested in anything i had to say, he made a hand gesture to come tomorrow after begging for him to hear me out. Now I'm stuck with a big size t-shirt for my occasion while i believe i got to the store on time to exchange. I've been with tfg for over 12 YEARS NOW but this is the worst service I've ever received. Your staff display a don't care attitude for customers. From my understanding if the store closes at 18:00 thats when doors can be closed, to think i was there 20 minutes before disgust me for the service i received. Sportscene Sam Ntuli Mall is a no go store and i won't keep quiet about it.