How can i get the shipping bill for a repair ticket

Hi

I'm form Chile and i've been living a real nightmare since my Elite Series 2 controllar start failing, I made a repair request from the microsoft devices web and i sent the control from Chile to the Texas Repair Center, since it still has warranty they sent me a new control, but they forgot to attach the shipping bill for imports and now the costoms house (postal office, aduana) won't realese my controller to the people from fedex because this missing document and now they been asking me to send it, but i don't have it and i have no idea how to get it

Please i need help, contacting someone from Microsoft Customer Service from Chile is nearly imposible, the web or phone send us to the virtual agent and from that you enter in a endless loop alway ending on the virtual agent.

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:)