CSO DESK OVEN NON FUNCTIONALITY

I will not talk about the instore sales service. My problems is their 1 deck 2 tray oven I bought has a manual with not information on how to operate the oven. I went to their maintenance section and they sent out a technician. He did not check the connection for the stove, which was done by a professional electrician but I wanted him to do his technical review. He listened to my questions tried to answer them but he was not confident in what he was saying because he called another customer who bought the stove from them trying to connect me with her. In a nutshell, I lost an order because everything I baked on the 19th of May 2026 came out under baked twice regardless of me adjusting the temperature and increasing the time to bake. I am not happy at all, I am even contemplating taking the oven back.