Back Market review: Awful service

I traded in my PS4 to Back Market after seeing a promo on playstation.com stating that I would receive a $50 voucher toward the purchase of a PS5. I received payment for my PS4 in a timely manner, but did not receive my voucher. After a few days I reached out to Back Market support to ask where my voucher was. I had to wait an entire day to receive a response that was obviously copied and pasted stating the voucher was contained in the payment confirmation email they sent me. I replied that the email did not contain the voucher, and asked what we needed to do next. Several hours have now passed without another reply from the agent. There is no phone number listed on their website either.