I just received an order from Amazon, today. The item was shipped from California to Indiana. The package arrived within days. And that was the standard shipping method.
Getting stuff from the USA to Congo takes months. And that's by container ship from the east coast. Then it gets to Congo and the process or the way to its final destination gets harder. The options to get those boxes from the Kinshasa to Kananga, the final 400 miles is limited.
There are no road for cargo to go by truck or road. In the past, it had to travel by air. Now, another option is for cargo to travel by boat and then by rail. And it could take weeks to months to travel the distance.