Nature Hills Nursery Refused to replace the trees that died even though they "guarantee their product" Omaha, Nebraska Nationwide

I began landscaping my backyard in March 2016. As I searched for plants online, Nature Hills Nursery continued to pop up. I decided to put together an order. However, I noticed that the one tree I really wanted was not available, the Windmill palm. The order was going to we'll exceed $400, so my mother paid for the first portion of the order for the $320 and I paid for the second portion of $170. The first order was on April 5th, the second portion was on April 20th. My mother had paid for the one year warranty and I wld swear I checked the box as well however, they say I did not. I immediately planted the trees and plants as they came in. One tree was broken in half and the palm trees were on their last leg. But in good faith, I gave it a good effort to bring them back to life. I failed. All the trees have died. My yard flourishes. I have beautiful flowers and trees everywhere except the trees purchased from this nursery.

So, I decided to contact them. I asked for the palms to be replaced and explained my good faith effort to try to nurse them back to life and got a demeaning and chastising response back. I continued to try to explain the situation getting nowhere. I then tried to call to talk to someone. I waited on hold two separate times each for over an hour. I gave up. From there it went downhill. They said I didn't get a warranty on the palms only on the other trees. I said fine please just send me the other trees. They said I have a credit of 109.85. But it was for trees only. I said I wld like ONE tree for 69.95 and they can use the rest for shipping. She said NO. She said I had to pay shipping with my credit card. I said no way. I wasn't giving them access to my Financials again. Not after reading endless reviews on their poor business practices. She said too bad. That the credit has to be used all at once, but it is only for the product. Their website states that "they guarantee their product." She continued to say that she wld void the one year warranty and refund me the percentage I paid for said warranty. That then I could order trees at half price plus shipping. I said what is that?? I have five dead trees from these people. I never thought people would be so demeaning and belittling. I rightfully paid the warranty on the trees I asked for and I asked for way less than the credit I have been given and they still will not send me a living tree. Regardless of the additional warranty I paid for, how does this behavior " guarantee their product?" I simply want one living plant, or the credit of 109.85 put back onto my card. I want something to show for all the money I spent. After that, I will never do business with them again. Please help. Thanks.