Travelstart booking non existent flights

My girlfriend booked a flight from Nacala to Maputo using Travelstart with Ethiopian airlines. When she gets to the airport to board her flight turns out there is no Ethiopian airlines flight available. She is in a foreign country and stranded at the airport and I've been on hold for 30 min trying to talk to a travelstart agent. The after sales service is terrible and I really dont know how a gross error like this can occur. Please assist