Apple has determined that some iPhone 6 Plus devices may exhibit display flickering or Multi-Touch issues after being dropped multiple times on a hard surface and then incurring further stress on the device.
If your iPhone 6 Plus is exhibiting the symptoms noted above, is in working order, and the screen is not cracked or broken, our Service Centers will repair your device.Service Process
Note: Wireless carrier partners are not participating in this program.
To prepare your iPhone 6 Plus for the service process, please back up your data to iTunes or iCloud.
For more details, check here.