FBM seller Refund Issue.

I have 4 refund requests that are 40 days old. I buy my shipping from AMZ , so AMZ sent them paid shipping label, they have not returned the item. I’m curious what happens ? Also, I have a chargeback. I replied my reasons why not to approve the change back . Does AMZ treat it like a refund ? Am I charged additional fees? Thank you 🙂