Bad attitude and broken products

I popped in to print some work documents a few weeks ago and noticed a TV for sale. Having asked the guy behind the dest a bunch of questions about the TV I decided I would buy it for my apartment. He assured me that it worked fine and that it was used for instore display purposes only . A few weeks later I came to collect it only to find that the HDMI ports didnt work . I went on to use 2 other cables and a different computer and nothing connected so I sent them a message to let them know.

Immediately I was met with defensiveness and a terrible attitude. The next day I went to the shop only to be flat out ignored by the shop attendant as he typed away pretending to be too busy to see me standing 2 feet away from him. After a few minutes of waiting I left and returned a few hours later and even then he could not have been bothered to communicate properly or even apologize for this inconvenience. Now I'm sitting with a faulty TV and all I've been told is they dont do returns and my it doenst seem like anything is being done to fix this issue .I'm angry and frustrated