Pep are infringing on our rights

My wife and I came in to get a refund on a purchase we made on the 9th of April at 11.15 of a laundry basket. We did not have the till slip but we had proof of purchase through the sms from our bank, the manager J J told us to call customer service because its against their policy then after doing so was told to tell them to call area manager they then decided to give us a coupon and here is the most clueless thing that happened in order for them to give us a coupon they looked up the receipt and found it but chose not to give us a refund which is directly against the CPA. As long as you have proof we should be refunded.