No refund after failure to deliver goods

I bought goods online at Banggoods.com and the goods were split into two orders. After a few weeks I started calling to track my order, they told me that the goods are at the local post office, after calling around and querying with Banggood I finally got the first order, Banggood told me to wait a few more weeks for the second order. After weeks and a couple of calls and emails later I got a response from Post Office SA saying the goods were returned to sender. I then spoke to Banggood and they promised to resend and gave me options to either get refund or wait, I chose to wait cause I was not in a rush. A few weeks later ( about six moths after I made the online purchase ) Banggood says they cannot help me because the order was made a long time ago.