Oh dear, things are not going too well for Apple are they, because just days after the launch of the iPhone 6 Plus “Touch Disease” repair program, they have had to do the same thing for the iPhone 6s with its unexpected shutdowns.
If your iPhone 6s suffers from the battery flaw where your phone will shutdown for no reason, then you might want to enter your details into this dedicated Apple page.
The iPhone 6s Program for Unexpected Shutdown Issues Replacement Process – You first need to choose your service option in the link above to have your battery replaced. You will then have your phone examined before being serviced to make certain it is eligible for this new program.
You also need to call your service provider to make certain the replacement service is available on the day you are to visit them. There are also steps you need to follow to prepare your iPhone 6s for the repair program, such as backing up your data, turn off Find my iPhone, and then make certain you erase all data and setting son your phone.