Viomi V5 Pro Vacuum Faulty Sensor

After doing a lot of research, I bought the Viomi V5 Pro robot vacuum last week. When the product came, I was happy to see how well made it was. But when I opened it up and set it up, I got a "laser distance sensor error" on a brand-new product. When I called customer service, they told me to do a reset and a few other things, but the problem was still there. They told me to take the product to the nearest service center, but when I looked it up online, I found that it was a common problem that had been reported many times. So, I used my right to an unconditional return from the store, Trendyol, and sent the item back. But my refund hasn't been taken care of yet. Viomi says that the product has been sent for testing, which they say will take 20 business days to finish. I won't take the product until I know what changes were made to the brand-new vacuum. This is a very bad situation that hurts the reputation of Viomi as a brand.