My Viomi V5 Robot Returned Unfixed After Noise and Suction Issues

We sent our Viomi V5 smart robot to the warranty service due to loud noise and reduced suction power. We were told that the device malfunctioned due to high voltage and that the repair would cost ₺5000, which would be covered by the Ankara EDAŞ company. However, when the device was returned, the issues were not fixed. Additionally, EDAŞ provided a report stating that there was no high voltage or any work that could damage devices. Now, not only is our device still broken, but we also haven't received a refund.