Samsung — i am complaining about samsung a50 handset

I am visiting service center from november 2019 regarding the complaint that it has an back body problem, when it is pressed from the back it have the sound like popup.. The speakers are okkay.. I have visited there 3 service center but the problem is not been resolved and around 8 to 9 rounds i have done of their service center.. One have just changed the battery battery which was in good condition and said that it has swelled.. I have bought the set on 5th of april the device is still under warranty.in this covid situation they are forcing to came to their service center again and again..