Wrong installation

I app**** for an account through Vox and they sent the supplier to install the device and the supplier installed the device less that 30cm away from stove and the device is directly exposed to cooking smoke. Immediately before their technician leave I told them I want it in lounge. He refused I contacted the service provider of Vox and they said they will come back and correct and never did and I complained to Vox and they responded that it's ok where it is and if I want to move it it will be at my cost. I told them and sent pictures and I told them I will courier their device and they refused and force me to pay cancelation fee which is the price of the devise now they sending laywers letters threatening me