O General - Defective AC supplied

I have purchased one O General Split Inverter AC (Model *.* t ** JCC) from M/s Goyal Radios, Sangrur (Authorized dealers of ETA General Pvt., Ltd) vide bill no. **** dated **/**/****. From day one I am feeling that said AC is not giving proper cooling. I have registered a complaint with M/s Goyal Radios two times but their technician after checking my AC told me that it’s working properly. I thought that this is due to inverter technology. But a few days back I bought another Inverter Split AC of Mitsubishi and installed it in another room which is bigger in size and observed that it's doing much better cooling than my O General, even its airflow is also very high. Then on **/**/****, I filed a complaint with customer care of ETA General Pvt., Ltd. vide Complaint No: CHA***********. The mechanic from M/s Goyal Radios, Sangrur came and replaced the condenser of the AC, but the cooling is still not effective. In the meantime, winters arrived and we have stopped using AC. During last summer season i.e. during the month of April'** to August'**, I have called nearly *-* times to the mechanic of M/s Goyal Radios, Sangrur, regarding the issue with the cooling of my A/c. Now in ****, when I have called their mechanic for paid service the same issue is there and he told me that another person will come and resolve the issue. But all in vain. Then again I have many times written to their customer care and other officials but they are not giving any satisfactory reply nor are they fixing my AC problem. Now they are asking that your AC is out of warranty. I feel cheated as the AC sold to me is of poor quality/defective from day one. I have spent nearly double the money (As compared to other available AC in the market) on O General, just because of a good brand and quality product. But very much disappointed with the quality and performance of the product.