I am very sorry for the issues you have encountered with your Samsung 43" NU6900 TV. I understand the frustrations and the inconveniences this has caused. Please contact Samsung Customer Support so that we can better investigate your issue and assist you towards a resolution or replacement.
You can reach us via any of the below options:
1) Phone: 1-800-SAMSUNG (ask for TVs) Available 8AM - 12AM EST (Mon-Fri) / 9AM - 11PM EST (Sat-Sun)
2) LiveChat or Email: https://www.samsung.com/us/support/#contact_us_for_support
3) Facebook Messenger: https://www.facebook.com/samsungsupport
4) Twitter: https://twitter.com/SamsungSupport
If you have not already done so, we invite you to register your new Samsung TV at: https://www.samsung.com/us/support/register/
Registering your product gives you access to easy warranty support, convenient opt-in to special promos & offers, faster troubleshooting & service, and quick notification of system updates.
Samsung is committed to providing the best possible product experience, quality, and value. We back this Samsung TV with a 1-year limited manufacturer's warranty, including authorized repair for manufacturer defect, if purchased brand-new directly from an authorized seller.
Again, I am very sorry for the inconveniences you have had, and hope that we will hear from you soon.
- Samsung Solutions