Viomi v5 Pro Robot Vacuum Repair Failure

We bought a product. "They disappear after the sale," as the saying goes, and that's exactly what happened. Viomi v5 Pro robot vacuum: Either the fan breaks or it won't clean. It's only been six months since we bought it, and this is already the second time we've had to send it for repairs. And they even gave us the Sunny guarantee. But their technical service is not up to par. When you try to explain the problem to them, they barely listen, and then, without saying a word, they just turn and leave. It's pretty frustrating. They ask if you have an appointment, and if you don't, they won't accept the product. It looks like Viomi and Sunny are playing hide and seek.