You've determined to the best of your ability that your device has been hacked. At the very least, you've determined that your device is demonstrating behavior that you cannot otherwise explain. The following are the steps you should take depending on the particulars of your hack.
Depending on whether your device is a Bring Your Own Device (BYOD) or is owned by your employer, the steps which you take should be similar. If you own the device, you may just initiate a device reset. Every device has the ability for a basic reset. In most cases, this will remove all the data and applications and place the device into an original setup state.
For example:
Apple: http://support.apple.com/kb/HT1430
Apple also has on online assistant at http://www.apple.com/support/iphone/assistant/
Samsung: http://www.hard-reset.com/