At the end of January this year, and few days after Zimbabwe introduction of a 100 trillion Zim $ note, Zimbabwe authority decided to add foreign hard currency (USD and South African Rand) to be used officially. The problem came after many companies and shops refused to use Zim $, worse was when even the street vendors refused to accept Zim $ because of its liquidity. Read Here as well.
Now there is much more crisis to the banking sector, banks lobbies are empty, as people come to withdraw money once in a month (when they are assured their salaries have been credited) to avoid transaction charges from foreign currencies which are higher, while in the past long queues were normal phenomenon. Some companies have decided to use cash terms rather than cheque system, which make Banks to have no work, no income.
Some of the banks had to give leave without pay for some of their staffs, other half paid etc.
Some Banks are much more worried now especially after they were "ordered" to centralise their foreign accounts through a special reserve account which is under control of Central Bank, it is said some of the money have been used by the order of Governor of the Central Bank without account holders consent or knowledge, and some of the money has not been returned to the respective accounts.
Zimbabwe currency is unlikely to return to the market in Zimbabwe for at least a year according to government statement.