Faulty Decorder from OnAir TV

Decorder was ordered and installed by OnAir TV. The decorder continuously reboots and I feel it is faulty. Rebooting takes several minutes. Meaning that some programmes are interupted. I have advised OnAir TV about this matter and that I would like to cancel the order since I do not trust their product. I sent that email on the 20th of January. To date there is no response from OnAir TV. I cannot buy a faulty decorder. As the issue continues. And i must pay R179 for 24 months for faulty goods.