Fedex are ********

I bought hair from China on the 25th November. My package was shipped within a day on ordering and arrived in South Africa in 3 days. Then Fedex called to inform me my package was held by customs and requested proof of payment. I sent proof of payment as requested. Fedex informed me that customs imposed a penalty of R1000 on my package and asked if i could pay for it. Yes i said yes since i didn't want to delay my package further. Now Fedex has issued me an invoice with an amount of R2 942.49 saying i should pay this amount for my package to be released. This amount they are requesting is 95% of my package value. How does Fedex calculate their customs. This amount is outrageous and i cannot pay it. Fedex i want my package and i cannot pay the amount you are requesting because it is too much & i cannot afford it.