https://www.fnbci.co.uk/contact-us/contactUs.html
When I opened my account, it only took a day or so to open. The website link to their contact details are above.
I have a USD Global Account with FNB into which I transfer funds on an ad-hoc basis. All is done via the FNB internet banking website. When you do the transfer, there is a short form that requires completing which FNB then submits to the SARB to obtain approval for the ZAR leaving SA. The entire transfer process takes about an hour from pushing the button until the USD's reflect in the Global Account.
Once a year in December, I then transfer the funds in the Global Account to the Channel Islands account. Again, this is done via the FNB internet banking website where you set up the Channel Islands account as an international beneficiary using the SWIFT details. Once the payment has been processed the funds reflect in the Channel Islands account within 24 hours.
I requested the Channel Island account to be linked to my SA FNB online banking platform so it appears as a separate account when I log on to FNB. You of course also get log in details to the Channel Island banking platform from where you can make transfers, payments etc.
I live in SA and only have an SA passport.
The only other bank that I know that allow SA citizens (that has no dual citizenships/other permanent residence status) to open a foreign bank account is Investec, though their one is UK Pounds only and you are allowed to have the UK account as long as you have a bank account with Investec in SA.
I have a call account with FNB Channel Islands denominated in USD. It is free of charge if you maintain the minimum blalance. You can opt for a full current account, which is a full transactional account with debit card etc but there is a monthly fee (that is waived if you maintain the minimum balance) and it is only available in UK Pounds. Since I have zero interest in ever living in, or be associated with the British, I opted for a the USD call account and together with the USD Global Account's debit card, it can be used for transactional banking should you wish.