I can certainly understand you being disappointed that you can’t exchange this defective TV so soon after purchasing this TV, and I am truly sorry if this was not handled as professionally as it could have been.
The store is correct that our return or exchange period would be 30 days from the date you took possession of this TV. After the return or exchange period has expired you would need to work with LG towards any possible resolution under their warranty.
I would like to look a little deeper into this, and I am sending you a private message to gather some personal information. To check your messages you should log into the forum, and then click on the letter icon in the upper right-hand corner of the page.