Yeah, until yesterday official rate was about 3100 BYR for 1 USD and today it's 4000, in Belarus exchange rate is set by government, and banks (even private) can not exceed it. Before the elections government loudly declared that there will not be any devaluation next year, and raised salaries for 30% without any economical reason, The most people didn't trust their declarations, (it wasn't the first time they cheated people) and many of them rushed to exchange offices and started to convert unstable and empty belarussian money to much more solid dollars. Now Belarus is experiencing a huge monetary deficiency. Because monetary reserves are on the critical level, and we are close to default, government denied sell currency to people from monetary reserve. So nobody can buy dollars the real course is about 4500-5000. Yesterday national bank raised limit of dollar cost to 4000, and so they at last formally passed the devaluation de jure. And again cheated their own people (. As I know today still nobody can buy currencies even on such high price... Why people measure their salaries in dollars... Our economics is very dependent from import, now many enterprises don't work because they can't buy currency to pay for imported parts and materials so many prices are invisibly tied to currencies. And when dollar is raising - all the prices immediately follow it.
You can withdrawing USD from cash point because you have an account nominated in solid currency, most people have rubles on their accounts and it's the same situation as in exchange offices.