Unfulfilled promises, invalid vouchers, zero customer service

I see that my experience with Cape Union Mart is not isolated because there are customers here with the same exact issue. A voucher was sent to me (unsolicited, just as a "gift" to customers) but the voucher rejected as "not valid" when I tried to use it, even though I met all the requirements. I contacted customer service and spoke to Lee who first said that I needed to create an account or log in before the voucher could work. I hadn't logged in before, so I did. The voucher still didn't work. I called again. Lee then said I must have an item on promotion in my cart. I checked my cart. No promotional items. Then he said he would have to research the situation and that I should send him an email. I sent him an email with an explanation and a screenshot of my cart. I didn't hear from him for 4 days. I sent the email again, copying the general customer service email address. Still no response. As a last attempt, I called the service number again and, this time, I spoke to a woman who said that Lee had a family emergency and that only the person to which a case is assigned can deal with that case. She said Lee was now back and promised to have him call me back before noon that day. That was two days ago and I still haven't heard from them. I'm not quite sure how or why they stay in business because they have no customer service and they are obviously not interested in selling their products.