Unable to make a purchase

Hi,

I am not able to make a purchase from the app store. I have made purchases earlier and it has been fine. I keep getting this error saying

my transaction has been declined. I tried using 2 different cards thinking one of my card might have a problem. But I know for sure that none

of my card has any issue. I recently upgraded to 10.11.1. Is this got something to do with the transaction being declined? Also, I changed my

apple id password as well. Again.... anything to do with that? Any help is appreciated.

Thanks,

Akki