Refused to help me with faulty cell phone

Last month I bought a Stylo cellphone in Pep cell JHB,yesterday I found out that it was not charging anymore so I decided to take it back to Pep cell store in Phumula. Germiston. Unfortunately my son lost the receipt but I had the original box, phone and charger. In the store they said there is nothing they can do because the receipt is lost so I left the phone with them there. I take responsibility for the lost receipt but when I buy a phone you scan it in the shop which means you do have records that the phone was bought in Pep, WHY AM I TOLD THAT YOU CAN'T DO ANYTHING BECAUSE I LOST THE RECEIPT? I want my money back or you fix the phone.