Hi Raghuraman
That is the correct behaviour when using data type enhancements. The original standard data type (that is referred to in your data type enhancement) will automatically show the additional changes.
To remove it, just delete your data type enhancement object. Once deletion is activated, you can view back the standard banking data type and see that the changes are no longer there.
Here is a guidebook on handling enhancement to standard enterprise services.
Enterprise Services Enhancement Guide
Rgds
Eng Swee