FedEx Do NOT understand the term WARRANTY

I'm starting to think that I will never ever get my parcel. It is a replacement part for something I bought that is still under warranty, but they keep sending me a email that says I should send POP I have send POP and Warranty agreement as well as the value of the parcel, basically every single thing you will need to get past customs, but they just do not reply. It's been two weeks and nothing is happening, the only time they mail me is when I call them.

When they then email me it's the same thing about they need proof of payment for the commercial invoice. Meaning they just do not understand the term WARRANTY and I keep explaining it to them. I DO NOT KNOW WHAT TO DO ANYMORE. Do you mind getting someone to sort this for me fedex PLEASE, I can't wait any longer.