Refused to give refund

Beginning July we bought a PC Screen from the Doringkloof branch. I was quite impressed with Thabo's service. He told me to keep the slip for the warrantee purposes. I explained to him that slips usually fade within a month and I am going to make a copy of the slip. He said that it is ok. The screen only lasted for about three weeks. I called Thabo and he said that there was replacement screens at that stage. But my only time I could send someone was this morning. And there were no replacement screens. So I opted for the refund. I sent our driver with the slip. Then Rudolph refused the refund, demanding the original slip. I explained to him what I discussed with Thabo. His reaction was, Thabo is not the manager. I explained to him the three R's in the CPA and he told me I am threatening him and hung up on me. Only when I insisted on speaking to the owner, he agreed to the refund. He is rude, unprofessional and not an asset to your business