TV problems, blaming me for physical damage.

I logged a return for my Hisense TV on 21 February 2021. The courier collected it on 22 February. I received an update on 23 February that the item is at the warehouse and a warranty claim is being logged. Checking back on 25 February by logging in, I see my return was declined and concluded. I received no communication whatsoever. I logged an e-mail query, only to be rep**** that the TV has "customer damage". There was no physical damage to the TV when I sent it back! The TV was standing in its usual spot, one day it was working 100%, the next day the screen was not working correctly. It was blurry and the pixels were jumping up and down, but the TV definitely had no physical damage! I tried different inputs, HDMI, etc. but the display was still blurry and jittery. So I packed it up neatly in its original packaging. I want this escalated and I want my TV replaced or refunded! If someone did physical damage to it, it had to be when it was handled by the courier or by someone else. There was no physical damage to the unit when I sent it back.

Hope to hear from someone SOON.