SRM Contract creation error in NWBC

Hi,

I have created a custom field ZREGION in SRM front-end and for its validation I have implemented a BADI "BBP_DOC_CHECK_BADI"

what my requirement is when ZREGION is invalid it should display error message and  contract should not be created

but when I am testing it from front end it is throwing error but at the same time contract is also being created.

Thanks in advance.