If you have turned your device off*, and re-synced your device with iTunes on your computer, and it did not resolve the issue, the game may need to be re-installed on your device. Unfortunately, this will delete the game's data. We can credit you with toxin to replace that which you purchased, and to help you re-build your cafe. We will just need a copy of the iTunes receipt of your purchase. Please reply to this e-mail and either copy and paste the iTunes sale receipt, or attach it.
To deposit Toxin into your account, we will also need your device ID. To find this, connect your device to your computer and open iTunes. Select your device in the left panel, then select the summary tab on the right panel. On the summary page, click on the serial number to reveal your device ID. If you did this correctly, the heading "Serial Number" should change to "Identifier (UDID)." You can copy the device ID by selecting Edit > Copy.
To turn off your device, locate the hold/sleep button on top of the device, at its right side. This is a physical button, not an on-screen one. Press the hold button for a few seconds, until a slider appears at the top of the screen that says "slide to power off."
To turn the device off, move the slider from left to right. If you don't want to shut it down, tap the "cancel" button at the bottom of the screen.
To turn the device back on, just press the hold button until the screen lights up and the Apple logo appears. Then let the button go and the device will boot up.