Poorvika Mobiles — mobile issue and not giving replacement

Address:

poorvika mobiles, kandhanchavadi bus stop omr road chennai., 600097

I have purchased mi a2 mobile on dec 31 2018 continuously i got issues like vibration not working, hanging issue, keep on showing ui is not responding, sim slot is not working, screen flickering, apps not downloading from play store by connecting wifi and mobile data both, sudden black screen while receiving calls i visited 4 time to mi service centre they reinstalled my os and service my phone 4times still my problem is not solving and finally mi service technician told me they gave swaping device that is the device is came for replacement i'm really frustated they dont do their responsibility properly they cheated people.