FNB business bank international payment is impossible

I have been looking at supply of stock for my business overseas. One of the options is to bid for stock in an online auction. Since I am a first-time bidder, a deposit is required. I went into my FNB branch to arrange to pay the deposit, and they directed me to do the payment using online banking.

I received an email stating that an invoice was required, but since this is a refundable deposit, no invoice was received!

Documentation was provided from the auction site to state why the deposit was required, as well as the amount, but FNB is just not interested - they want an invoice for a refundable deposit!!

I use FNB as a business bank, please can someone amend the rules to reflect business in today's day and age. If I cannot make a payment using online banking is there someone in a branch that can help me. In this economic environment I should be able attempt new avenues to keep my business going!!

It is extremely disappointing that one can make international credit card payments with no issue, but a transfer using a 'business bank' is near impossible