Samsung - Defective refrigerator received

We purchased a Samsung refrigerator on **/**/**** from naval canteen Vizag. Model no rt**m*** of ***-litre capacity. The mechanic came to install it on **/**/**** and insisted upon us to use * amp switch which burnt out after * days. We then installed a ** amp switch. Right from the first day, the lower door of the fridge was making a knocking sound each after * or three openings. We tried to empty the entire fridge and check it. The sound continued.
At last, we made an official complaint to their service centre on **/**/****. The mechanic came to attend the complaint on **/**/**** after * days. He checked the door and declared that the door is defective and that a screw is to be cut and the door has to be installed again.
We didn't agree with the cut and paste method and asked for the replacement of the fridge. We asked the mechanic to provide us with the phone number of the higher officials to talk. The mechanic denied it instantly.
From then onwards till today no official from Samsung has bothered to contact us. The same mechanic and then one Mr Sathyanarain have been insisting to allow them to repair the door and asking us to use the defective piece.
We are aghast. We have just shifted to Vizag on **/**/**** and from then onwards so many mental tortures are being faced by us. Please look into the matter and replace the fridge immediately. We do not want to compromise on any level lesser than a replacement.