CedCommerce Amazon Channel

I'm saying this with regret, but this has been a huge disappointment.
I've been trying for two weeks, but the app keeps throwing errors — despite providing all required information correctly. Both the SKU and barcode are valid, and the system even says the product was uploaded, yet due to the error, it never appears on Amazon.

However, when I enter the exact same product manually on Amazon, it works in two minutes without any issues.

Unfortunately, your customer service is even worse than the app itself. They don’t provide real support, only superficial replies, and always blame Amazon without offering actual solutions.

Among all the Shopify apps I've used, this one has by far the weakest customer service.
As things stand, I’m not satisfied with the app at all and will be uploading my products directly to Amazon from now on.