Every country have their own trick and step, like at my country I'm use vip.bitcoin.co.id
on that market exchange I can sell coin with IDR (Indonesian currency)
after we Get IDR, I sent IDR from market exchange to my ATM card,
So that meaning, they get their money from bank, but not directly.
I think you should looking for recommended site to do it, which the best site at your country. and don't follow some people look suspicious. maybbe that can be fake site.
and I hope thia little knowledge han give you an imagine how it work.