Women's Hipster Bikini Bottom Blue

Ordered this on sale, and a matching top. They canceled half of my order, so the top never arrived but they continued to ship the bottoms even though I intended it as a matching set. The bottoms arrive, but there's no top to match, so I decide to return it. There's no option to return on the website, despite saying free returns within 30 days. I contact customer service about starting a return they say it isn't eligible because it was final sale. I respond saying it was not listed as "final sale" just sale on the website. They respond to that message saying it can't be returned "it's a safety issue". I can'imagine what the safety issue is, and they failed to elaborate. They didn't honor their return policy. Even when the reason I'm returning is because they failed to fulfill the second half of my order (stating it was out of stock even though it is still available for purchase and listed as in stocks on the website)