Paypal WPP CVV Validation Problem

[vasuparashar]

I have a store which I customized from some Company (PERCEPTION SYSTEMS), to have Payment option through credit card linked with my Paypal Business Account. They integrated and went away. Now after few weeks I analyzed that if I run the transaction without entering CVV number even then the transaction is going through which should not be. It should validate the things right there for the user as Paypal is integrated. I asked that company but they are saying that I didn't test that time so they will charge extra, it is very unprofessional.

 

I need help from this community to let me code that CVV validation in my system. I know some php, even I am .Net Professional and integrated paypal in .NET. If anyone of you can guide me that I think with your help I can fix my problem.

 

Thanks in advance.