Bad customer care

Good day I bought a jacket, socks, and a boys Japon by jet on the 11 July 2024. I went by jet cape gate were I bought it cause it's a 2xl and I want a xl jacket. Now they refuse to change my jacket cause I don't have a slip. I ask the manager if she can't go back on that they to retrieve the slip and she refuse. I want to change the jacket for the same 1 but just a smaller size. Please see attached my proof of payment . I can't wear this jacket it's to big. I can't remember if I did took the slip or not cause I was in a rush. Hope to hear soo from you Regards Natacha Erasmus ***