Stranded items in Amazon FBA

Hi
I have 7 SKU's stranded on Amazon FBA. Amazon Seller Service have not been able to help me. Can anyone either guide me through it or fix it for me please?

I have this instruction from Amazon, though I cannot identify where to place the code that they gave me:

----------------------------------------------

We understand that you are ASIN B0C5VSKB1S, B0C5VQYDK7, B0C5VQYDK7 and B0C5VPY7B5 . Please don't worry, we will try our best to look into this.

Your listings are stranded because they have multiple fulfillment channels saved in the system. As a result, the listings were switched to inactive. You have to update the offer with this stock file and the upload so that only AMAZON_EU_RAFN is stored with us.

This will make the offer active again.

Note that the process can take 24 hours.

Kindly submit a fulfillment channel switch Feed to remove the incorrect channel. You need to submit partial update feed and mention the correct channel "AMAZON_EU_RAFN" as in the feed to remove the other exchange.

Inventory file templates:
https://sellercentral-europe.amazon.com/help/hub/reference/1641

Please ensure that they are not missing any required attributes

As our valued seller, your satisfaction is our top most priority

Hope this has helped. It was a pleasure assisting you. We apologize for any inconvenience caused. Please feel free to contact us anytime. We are happy to help