you can go to any shop and get mastercards and top them , there all legit and work fine.
you can also buy gift mastercard with set fees on them , they also work fine .
I don't think there many virual cards around working these days .(( bing or adwords))
the only other way ,is a person has spoke to there own bank, and setup vcc as a service , but there not suppose to hand them out or sell them , there just personal vcc accounts from there business bank.
vcc accounts get stoped very easly as the number on the account identifies it self as a specefic vcc , so business like adwords , facebook , bing collect that info, and if notice to much activaty from the vcc specefic number and connected to diffrent ip and other stuff band the whole vcc service.
becouse that happening a lot know days, majority of vcc wont work with any advertisement company .
Pls how should i use a US vcc to register on google cloud when i am not in the US in order to avoid google asking for verification documents? I used a vpn without luck and later read that vpn and proxy will trigger verification