Jet service sucks. They are giving me a hassle to refund my money

I am extremely frustrated with the kind of service i am receiving at Jet Bridge City KwaMashu. On the 20th December 2018 i was purchasing two school shoes and i used my debit card for payment. While the cashier was processing the payment he said his system was stuck but the payment was already processed and approved via the speed point. Due to his system being stuck I could not get the store receipt so from there I also could not take the items i was purchasing as it does nt reflect on their system. Since then my money has not been refunded, they keep on telling me stories that they are investigating the matter. I have also called the customer care but they are also not helping. My ref from customer care is: ********** 2402/go.