Non-delivery of purchased items

On the 5th June, I ordered clothing on the website that showed it was in stock. On the 8th June, I received a Whatsapp message saying that their shipments are delayed with back orders. Every week they kept to the same story about delays, firstly due to COVID and then because of looting. Every time they kept referring me to their shipping terms which is 21 days plus an additional 28 days. It is now the 12th August and I still have not received my goods. I've requested for my refund and they have said I can only request for it, 90 days from my purchase date (just another delay). This has really been the worst online shopping experience.