Fedex fails to deliver

My wife and I used Fedex to transport a package from a friend in the US. The site told us that delivery would take less than 2 weeks. Our package has been lying in Jhb for a month now. We have made numerous calls to Fedex and escalated the matter many times. We were eventually told that they require an invoice from us which we emailed to them immediately upon their request, and they still failed to respond. It's now been 2 weeks since we sent the invoice. We have very busy schedules at work and we have to take the time out during the day to make these calls that can take anything from 10-20mins. For example today I made 3 calls, and after selecting the various options on the keypad I ended up holding on and the call got cut after 10mins on each occasion. We have also escalated the matter on a few occasions when we do get through. We are always told that someone will call us but no one ever does. We were also given the number of a manager who works in Imports called Sanjeev. Whenever we call the landline number, no one ever picks up. The cell number that was given to us, just rings and goes to voicemail. We left messages for him but he never returns any calls. We also received an SMS to urgently send an invoice to customs but there is no proper email address to send same to. We are at our wits end and have no idea what else we can do to receive our package.