Walmart SGIN Official Store No return because it was from a third party in CHINA Pasadena MD

I purchased a SGIN 15’ Laptop computer from Walmart on August 3, 2023. I spent $275.59 plus 59.00 for protection plan insurance, the seller was SGIN OFFICIAL STORE. At the time I assumed that I was purchasing from Walmart. It had a 90 day return which again I thought it was Walmart return policy. I turned the computer on and it disconnected from the Wi-Fi. It would not stay connected to wifi my phone, tv, tablet, and another laptop do NOT turn off it is this laptop I thought it was my wi-fi, I hired an IT man to come see what the problem was. He said he did not know why every 20-30 min the computer would shut down it would not keep online. It constantly disconnects from the internet for no reason, all my other devices on that network are fine but it disconnects from the wifi. He said it has to be the computer. I took it back to walmart to return it for a refund. The manager told me I could not it was a third party. I had no idea what a third party was, they explained that SGIN OFFICAL STORE sold it to me?? It was called Walmart Marketplace. I said then why do you have your name on it if you do not stand by what the third party sells. She suggested that I start a return online. I started my return on Walmart contacted the seller through Walmart. The receipt states that Marketplace sellers have different return policy. China said I went over 30 days but I said Walmart policy is 90 days. I had to text CHINA again, they got right back with me (SO SORRY) they told me to go back to Walmart. I went up and talked to three managers, all of them tried to get a refund because the employees agreed with me. They told me to go through my protection plan insurance that I had purchased for 59.00. I put a claim in but the employee said that was the only computer that was NOT COVERED. Why would Walmart sell me insurance that did not cover my item?? This is not my job to check to see if the computer was covered under their umbrella. Walmart just took my money no flag went up and said (we do not cover this item under the insurance). This laptop is crap and won't hold a charge, tried getting a refund and it's apparently sold by a 3rd party even though it's on Walmart website and fulfilled by Walmart