I emailed LG also, and this is the reply I got, like yourself not happy with LG.
Thank you for coming back to us, we have had a response from our Technical Team. They have advised that this will be a limitation of the Backlit technology used for these TVs. I do apologise but as this is a backlit TV the Colour and clarity will degrade as the viewing angle increases as the TV is designed to be viewed from the front. As this is not a fault of the TV but a result of the Technology we will not be able to offer to repair this as you will get the same result from a new panel. I do apologise for any frustration caused.
I hope I have helped you today, but if you have any more questions regarding this, please do not hesitate to get back in contact with us for further assistance, we would be happy to help you. I hope you have a lovely day.