Poor customer service

I went to Jet Store at Clear Water on the 23 of December 2020. I bought my son school takies... when i got home only to find out that they are a big size. on the 30 of december i went to Jabulani Mall to try and exchange as i relieased that i have lost my slip i just wanted to get a smaller size.. The response i got was i got was i could not exchange the lady tried explaining that since JET was bought by TFG they dont do exchange without a slip, i have been buying at Jet for long time and i could do a exchange without a slip now that things have changed why are we not informed as customers that we can not exchange when we lose our slips. this is really bad service from Jet because they dont even put notices to inform us about this. firstly when i was buying why was i not informed. called their head office last week spoke to a guy named WAYDNE, he promised to get back to me until now no one has got back to me.. if this is how TFG Works then the are ******** and robbing us as customers, i need to know if this is in the Cusumer act RIghts.