It sounds like your phone screen is zoomed in but is not responding to triple tapping to zoom out. You can indeed configure the accessibility options in iTunes on your phone when you hve it connected. This article will help you do that:
iOS: Configuring accessibility features
Managing accessibility features using iTunes
- Connect your iPhone, iPad, or iPod touch to any computer with iTunes installed.
- In iTunes, select your device.
- From the Summary pane, click Configure Universal Access in the Options section at the bottom.
- Select the feature you would like to use and click OK.
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You have Zoom on... double tap with three fingers to turn it off. Then, go into Settings > General > Accessibility to disable it.