65a6130UW not working as advertised

I have been getting the below errors since purchasing the tv

1. When streaming and the network drops, the TV freezes and I have to disconnect the mains 2. When enabling the HDMI 2.0 "Extended Features" for 4k output, The DSTv HD loses sound, thus I lose the features for my Ps4 as I have to disable it 3. WiFi setup lost 4. Netflix UI-800-3 Error 5. 5ghz WiFi network not being picked up

A technician came out and did a firmware update but all the problems still exist and happens daily now. I was told that its my router that is the problem yet no other device is having issues except this TV This model series is clearly defective and they should refund all customers