Normally the liquidation of offshore bank accounts takes a couple of days to about a week. In some cases, it may even take 2 to 3 weeks. So, there is nothing that much to worry about it even if it takes a bit too longer.
Agree with riskprocessor.. and as already mentioned, a phone call or fax or postal mail to the bank is all what is required to get the account closed.
It was used to be only 1 week now it takes months if you at all get approved. Thouse who where luckily enough to get a bank account there should do everything to keep it.
Second that it depends very much on how the workload is at the bank and if you provide all documents right away or if the Agent or Bank has to request documents on several occasions.