Before you buy a new cell phone or new tablet, please try the following procedure to repair your device. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card. It is impossible to recover your data after doing a hard reset, so online backup is always important. For all of your data, a backup should be done on an external device, hard drive, raid system or media.
Samsung Ace Plus S7500 hard reset key combo

Back UP all of your Galaxy Ace Plus S7500 data first!
+
+both Volume
Press and hold both Volume + HOME + POWER/LOCK buttons together.
Samsung Galaxy Ace Plus S7500 soft reset
To soft reset your Samsung Galaxy Ace Plus S7500 android phone simply take out the battery and reinsert it.

OR
In dial pad screen: key in *2767*3855#