My headset jack broke off inside my phone and I cannot make calls or hear anything. Can I turn off the headset mode?
Unfortunately not without rooting your phone. Your best bet's going to be to remove the headset jack. If it's not reachable with any normal tools, you're going to want to use something thin and strong, like a toothpick with a filed-off end, and apply a small drop of super glue to the end of it, then VERY carefully insert it into the jack, press it firmly against the end of the headphone jack you can reach, hold it there for about a minute, and then carefully remove it.