where can i use maestro card?

In ATM?

Why not use your maestro card to buy a prepaid gift card (visa or something like that) and use that to add funds to your account?

I think you're mixing things up. Maestro is a bank card, not a creditcard.
If it is a creditcard that you're talking about, then you should probably select MasterCard when you try to order something online.

Where are you from?? Try Amazon I'm pretty sure they have steam wallet things, but it's more expensive than directly buying though steam.

Had the same problem myself, steam doesn't accept this card but what you can do is go to some other site and buy steam wallet card from there using your debit card and then redeem the wallet code they send you. Simple.

try paysafe. you can find one at globul or telekom

Use it on me if you like I don't mind :P

Go to your bank. Request an eBanking account. When you get that, log in and create a virtual MasterCard or Visa (it's just a number that is created instantly; you don't get sent a card or anything.) Load funds into that card. You then use it as it were a credit card. It is NOT a credit card (meaning it's not possible to overdraft it,) but it looks like a credit card when you do online purchases.

That's what I do, and it's been working great.

Thanks for all the help guys, I just bought cs:go for my other account from G2A althuogh they charged me for saving the children(1 euro) without my knowing but ohwell..

For next time just get a prepaid credit card. Around here you can't buy them in the store. Just buy one online (skrill is a good one). You can transfer money from your bank account on that card and then you can use it as regular credit card.