Exchange foods refused

Good day

Today I went to Mr Price in Promenade I told one of the managent ladies at the till i had no slip but I have proof on my bank account that I bought the stuff at Mr Price. I also said I dont want the money back I wana exchange because both pairs of shoes are to big for me. She said unfortunately they can't help me because of the looting. I don't know what the looking has to do with me if I paid for my stthings and I have proof. I do think this is bad customer service as I'm a store manager my self and we have to help a customer to the best of our ability. I suggested that she contact the Mr Price I bought the items at and ask for receipt because its about a week ago and the looting happen a month or 2 ago. She kept on saying they won't help me because of looting. I just think this is lack of service.