Samsung - Chabra communication Moudhapara samsung customer service

S pen disconnection, call dropping, no call waiting notification in between the call I.e beep, battery drainage (before had to charge * * times a day now * times a day after service), heating issues. *st time when my husband visited they took the phone for service n changed the battery n returned back n next when I visited the service centre they denied doing the service for free saying it has a dent on the phone so if we change the motherboard it will be chargeable. They told before it had no dent n now it has dent so cant do service without charges. I told it has dent from the *st week we bought the phone as it fell down. They were over confident saying we have seen properly it had no dent before n now it has dent. When asked for cctv footage, they denied saying they can't share later they told they don't have the footage as the camera isn't working