Hisense :Substandard product and useless guarantee

I bought a Hisense 75 inch Q7Q TV last November (8 months ago) from Makro I also bought a heavy-duty concertina type wall mount to mount it on.

It was solidly mounted to the wall in my lounge.

About four weeks ago I pulled the TV forward on the mount by gripping the top and bottom of the screen (to dust behind the TV). The TV was on at the time and I immediately noticed an A5 size black patch appear in the top right-hand corner of the screen, shortly thereafter the whole screen image started ghosting. I contacted Hisense (Makro instructed me to contact them directly) with a guarantee claim and their technician eventually arrived about a week later, inspected the TV and told me that they would not replace or repair the screen because it wasn't covered by the guarantee, and that I should have known that these screens are fragile and break easily.

I have gone through the instruction manual with a fine-tooth comb and find nothing stating that the screen is so fragile that you cannot move it by holding the edges of the TV. The Hisense guarantee isn't worth the paper it's printed on and they appear to be knowingly selling a substandard product.

I have checked with friends who have the same size and similarly priced and mounted TVs (Samsung and LG) and none of them have had this kind of issue when moving the screen.