CS:GO keys don't count automatially towards the credit. You need to deposit them via https://dispenser.tf/myshop/#KEY_CREDIT (horrible conversion rate though, currently 1:1 but even at its best you won't get better than 1.06 credits per key) or you can sell them on cs:go key market https://dispenser.tf/market/26191/ (better rate, but it takes time to sell).