I had a really bad experience with Zuji in November 2017 and I would recommend NOT to use their service. I booked a flight from Singapore to Vientiane, Laos. The price of the tickets was deducted from my bank account. When I arrived at the airport, I was not able to check in, my name was not in the passengers list. I had to call Zuji customer service. I spent 45 min trying to explain to them that I still wanted to be on that flight. It was a long and painful talk since they considered that I wanted to change my flight (which was not the case) and they would not explain to me why I was not on the passenger list. An experience that no traveller would want to face when going to the airport.
I complained to Zuji customer service by e-mail on my way back, especially because I spent ~70$S on phone bill, due to their mistake. I wanted my phone bill to be reimbursed. During 4 months, I sent reminder e-mails to them, and they always answered that my case was escalated to their manager and thanking me for my patience. When I told them that I would not wait any longer and that I would take further action, they stopped answering me.
PLEASE AVOID ZUJI IF YOU CAN. They will not help you save money, quite the opposite.