You can try these in case you downloaded corrupted or incompatible Java midlets or other media, which are causing problems with the phone.
*2767*JAVA# Java Reset and (Deletes all Java Midlets)
*2767*MEDIA# Reset Media (Deletes All Sounds and Pics)
*2767*WAP# Wap Reset
*2767*CUST# Reset Custom EEPR0M
*2767*FULL# Reset Full EEPR0M (Caution)
For example : *2767*JAVA# would be keyed in as *2767*5282#
Note : Not all codes will work with SGH-C100.