Carvana complaint: Carvana refused to resolve my issue

I ordered a Nissan Frontier truck in June. This isn’t really about the truck itself, though I will say that when it was delivered, it was not clean on the inside and had wrappers and loose pieces of food under the seats.
45 days passed, and they did not send the registration. I would like to stress here that I attempted to contact Carvana about 7 days in a row and have never had a more frustrating experience. The first person I spoke to said he couldn’t fix the registration timing issue, but promised that Carvana would issue me a check worth one month’s car payment. At this point, I had to get a rental car as I couldn’t drive with expired plates. I was told to call back next day. The next person I spoke to said there was no record of me being promised a check and that they couldn’t do it. He gave a run around about how he would try to contact the other agent to see what happened. I was told he would call me back. He did not. Thus I followed up every day that week, each time speaking to a new person and having to start all over with what the issue was. EACH person promised to research the issue AND….that they would call me back. Let me stress that I never once received a call back or any kind of follow-up.
I asked if I could escalate the issue and was flat out told no. Thanks to Carvana, I was $500 in the hole for my rental car. My registration arrived 3 weeks late. Never have I experienced such inefficient customer service….I felt that I was completely lied to and it’s so frustrating that there were no repercussions and that I wasn’t able to get what I was promised.
Please do not use this company. They do not care about their customers at all.