Poor service from subcontratcor

Good morning all, my issue with Fedex is when they subcontract work to other courier services such as Amerex. I always order darts and asseccories from the UK and I don't mind paying the high shipping fee in order for my goods to be delivered fast but when my package has been in South Africa from the 01/12 and still not delivered by the 18/12 then I have a huge problem with that especially when I emailed the courier company a copy of my I.D as well as the commercial invoice, I have now requested the goodies to be returned to the sender but now the package is still being held up by the courier company instead of having it immediately shipped out, could somebody from Fedex urgently contact me on my email address *** to help speed up this process as I need to claim a refund from CUSTOMS as well as the as the shipper