Not willing to release authorisation on a Trans.

I purchased Items online through Paypal and when doing the purchase on the 30th of April, the amount was taken out of my account and placed for authorisation. On the 7th of May when the vendor shipped my order, they put through the amount again to now take the money which they have reserved on the 30th of April out of my account although FNB neglected to link the two amounts on the 30th and the 7th of May as applying to the same transaction and now double the amount was taken from my account. I have phoned customer care who said that I have to speak to paypal, who told me the first transaction was the reservation of the funds and the second was when the funds were banked and that they cannot help and FNB should help. FNB tells me they cannot help and I need to either speak to the supplier or they can send me a dispute form where I can dispute this which might take up to 7 days to sort out. If not the money will be on hold for 6 months before being released. This is my money, in my account and is one transaction that should have gone off. I want the hold to be released on the transaction of the 30th of April and the money to be available in my account straight away. UNACCEPTABLE!