Store has no records of receipts of purchases more than 3 years ago!

I have had mediocre assistance from the House & Home pavillion branch. I purchased a Tv from the store on 29/12/2020 and the Tv is currently under warranty which was registered with the provider (Hisense). Over the weekend the Tv is not tuniring on so I sumbitted a claim with HIsense but they require the proof of purchase. I have done renovations at my home and cannot find the receipt and Hisense cannot book the repairs without this. I called the store for a receipt reprint and was infomred they changed systems and their data is only stored for 3 years so they cannot assist. Surely records should be kept for longer periods to assist clients. receipts fade over time anyway. Their processes need to be changed. Now i have to look at incurring additional costs to repair or replace my TV because the store cannot locate a receipt!