If you look at your schema you are trying to select rows based on a timestamp but the column AuditChrt_TimeStamp is a char(10). That is not going to work.
The very first snippet of code you showed was binding '2013-08-01 00:00:00.000' which is also way too big for a char(10). I incorrectly assumed you actually had a timestamp column. In the future it sould save time if you provided the schema at the same time.