Spree does not process refunds

I have ordered items via Spree.co.za on 18 February 2018 and logged a return for 5 items worth more than 2,000 Rand on 26 February 2018. The items were only picked up by FedEx after I called three times to remind them of the return. After the items were picked up and I saw that they were not refunded after 14 days, I called the customer service and they said they did not know what the problems was and would call me back, which they never did. I then called them three times again, same problem: "We don't know what the issue is, we will call back". They never called. When I asked to speak to the manager, she told me that according to their information, I had never returned the items to FedEx. When I told her I did, (unfortunately FedEx never gave me a receipt, which by the way they never do!!!), and even gave her the name and number of the FedEx person who collected the order, she said that was not proof enough, and I would have to provide them with the full name and number plate of the FedEx courier. It is apparently my job to proof that I returned the items. I was furious and tried to get the information from my office park, which they weren't able to give me, so long story short...it's been almost 3 months and I never received my refund...More than R 2,000 lost thanks to extremely bad customer service! Needless to say I will never ever order at Spree again.