I had a letter that I needed to get from Mexico to the US Social Security administration in one day. I used DHL with a guaranteed delivery. So, they took about $50 for the delivery, took the letter, and got it to Cincinnati for DHL delivery to Pennsylvania. It delayed in customs a few hours, and then instead of delivering it - they put it on a plane to Leipzig Germany, and it got stuck in German customs for a weekend.
Then Monday, they put it on a plane to New York, where it got to go through customers again and it finally got delivered 4 days after sending - on an overnight service. They promised a refund. THEY F*CKED ME - they offered the equivalent of $8 of credit. DON'T USE THEM - THEY ARE INCOMPETENT and LIARS.