Diakin India Pvt Ltd - Inverter AC PCB got faulty very poor service from Diakin

The Daikin inverter AC quality is very poor. I purchased * inverter AC in **** both are not running fine after * year only. First AC cooling coil has rusted within the first year only another AC PCB part got faulty. I booked a complaint on **th Aug ****. The engineer from Daikin visited on **th Aug ****. The part was supposed to be replaced within *-* days but I have been trying to enquire on a daily basis from Diakin customer service. They are not ready to give any ETA for part replacement. * days back they said they will replace the part on ** Sept ****. They even provided the engineer number. When I called the engineer he said he doesn't have the part yet it will take more days. I have been sleeping without AC for days now how torturous it is. Diakin product quality and service quality is horrible. I want to get the part changed at earliest and a written apology from Diakin.