buying with csgo keys or steam wallet card

my current subscription is gonna end by jan 1st. and my friend has declined to buy me so i cannot pay online now.
So just wanna know is it possible to buy subscription with steam wallet card
and how many keys do i need to give for 1 and 3 month subscription. mark wont reply to me on facebook so had to post here

Just wait until he replies

well thats the thing the message is already seen but he wont reply =/