2 x faulty products

A while ago, I bought a Volkano Adapter (https://www.incredible.co.za/volkano-x-core-hub-series-usb-type-c-to-3x-usb-3-0-plus-powe) and it didn't work when I took it out the box. I went all the way back to Incredible Connection Cavendish and told them this, and they took about half an hour of begrudgingly testing it before confirming it was in fact an OBF and giving me another. Then lockdown happened and I hadn't been using the new one for a while, when I tried it now, the USB-C port doesn't work. I don't have the slip anymore because it was from a while ago and I didn't think I'd be sold another faulty product. Now, even though I believe there was a warrantee on it, I am expected to go through bank statements which aren't available anymore, even though I paid by card and should be on the system.

Bottom line is I was sold an expensive faulty product twice and now I can't do my work properly. I've been a loyal customer at Incredible Connection Cavendish for years and I'm unhappy that I've been sold two faulty products and then the onus is on me to sort out the problem. I find this unnaceptable.