My Viomi V5 Pro Robot Vacuum Not Fixed After Service

I bought a Viomi V5 Pro robot vacuum on August 1, 2023, but after only a few hours of use, the main wheel started to act up and the vacuum stopped working. On October 1, 2023, I took it to the service center, but they told me they couldn't fix it there and would have to send it back to the factory. I said yes to their offer, but it took them more than a month to send it back to me. When I got it on February 24, 2023, I saw that the problem was still there and that nothing had been fixed. I think they're laughing at me. This is not okay, and I want them to take their jobs seriously and fix the problem. I'm very upset by their lack of professionalism.