Uncleared amounts hell

If I could give NO star that would be better - absolutely ridiculous service! I am currently travelling in the USA and tried ordering a gift online on Amazon.com. Within an hour, Amazon tried sending 8 authorization transactions to my account, because FNB kept on declining the requests. They were well aware of the fact that I am traveling in the US as I did inform them before I left and have been using my card here constantly since mid January already. I eventually had to call Amazon to cancel the order. However, the amounts charged via those authorization requests (totalling almost R4500) is now stuck in uncleared amounts on my account. Amazon confirmed that they never received any of the payments as they kept on being declined, so the problem is with the bank. I have been stuck without money since Thursday with no one at FNB being able to help me. I have submitted 3 versions of dispute forms already, spoken to Customer Service, Disputes Department, and the Private Clients Suite on no less than 9 occasions combined without any help. I was even told today by the Private Client suite that their system was slow and they cannot access my account, placed my on hold for almost 10 minutes after which I eventually just hung up. It is absolutely ridiculous that my money is stuck in unauthorized payments because of something that clearly went wrong on the bank's part, but no one is willing or able to assist in reversing that. In the meantime, I am stuck in a foreign country since Thursday (3 May) already without any money in my account... absolutely ridiculous!