Per Banxa.com, "Banxa is an internationally compliant fiat-to-crypto gateway solution for exchanges, wallets and other cryptocurrency businesses. We offer global and local payment methods with no chargebacks and easy integration to your platform."
When you verify with ShapeShift, you have not yet verified with Banxa, so if you would like to buy crypto with fiat, you will have to verify with them as well. To find out if you country is supported, see here.
If you are having trouble with your fiat-to-crypto exchange, please contact Banxa at email@example.com.