Goods Proof of purchase issues

We bought a Defy Hob and extractor fan at Game Store Shelley Beach KZN in October 2021. I wanted to return the goods unopened and in original packaging in beginning January 2022 but unfortunately I lost my proof of purchase. We went to Game Store in Shelley Beach beginning January 2022 informed them about the situation and they said they will have to contact Head office and ask for a reprint of the proof of purchase ànd since then and today the 26th January and after numerous phone calls and Store visits they are still have any solution or reprint ready for us they keep on telling us that we must call this one and that one and not even the Store Manager at Shelley Beach is hiding from us when we went about 6 times into Store the Manager is not worth to be in the position he or she is.